This is a TAS of 'Mighty Bomb Jack' for the NES that completes the game as quickly as possible with "Any Ending" (aka any%). The "Best Ending" requires collecting special items hidden in a pyramid's labyrinth so that all three members of a royal family, and a secret treasure, can be saved at the game's end. But for "Any Ending", no items are required and only the King is rescued. In previous submissions for this branch, warping was used in all 16 Palace Rooms because it was believed that was the fastest way to get to the end game area. But while I was putting together a full game map I found out that if you fail the warp in PR 4, you can take a shortcut through some of the standard labyrinth rooms to get to PR 11. This saves about 11 seconds in the TAS. The warping strategy is then used again from PR 11 to 16 to get to the end of the game.
All inputs in this TAS were manually input by myself, no inputs were copy/pasted from other TASes, although other TASes were reviewed for routes and tactics.
In these notes I will describe various game mechanics and TAS tactics to help with understanding the run, as well as a breakdown of which tactics were used in each stage.
SPECIAL THANKS Before continuing, I wanted to give a special shoutout to three people who have been instrumental in helping me optimize this TAS.
Firstly, Ktwo has helped guide me towards a number of resources that improved my understanding of the game, and also came up with some route improvements that will be specified in the stage breakdowns. The first version of the TAS I submitted was already faster than a previous submission for this category/branch by Guybrush, so I figured I was on the right track and didn't need to analyze his TAS. But under Ktwo's recommendation I took a look at that TAS as well as Hisatoki's 'Best Ending' TAS for routing and helpful tactics.
Secondly, Threecreepio figured out some details about the game's movement mechanics that allowed me to optimize the TAS even further with sub-pixel manipulation. He also discovered a pause-jumping trick that made opening chests and breaking blocks a little faster.
Thirdly, a user by the named Procyon on put together a bunch of awesome info, most important of which is the "shortcut" that helped cut 11 seconds of the TAS. He says he found it in a Japenese strategy guide.
  • 3D1 - Sub-X Pixel, 3D3 - X Pixel
  • 3D7 - Sub-Y Pixel, 3D9 - Y Pixel
  • 3E6 - Sub-Gravity, 3E7 - Gravity
  • 3C1/3C2 - SubX/X when the screen in moving
  • 3C3/3C4 - SubY/Y when the screen is moving
  • FA - Jump/Hover Counter
MOVEMENT MECHANICS & SUB-PIXEL MANIPULATION Jack's movement along the X-axis is fairly consistent, alternating between 1 pixel and 2 pixels because the sub-X pixel movement is 1.5 pixels per frame. The only thing that can slow down horizontal movement is bumping into a barrier. But Y-axis movement is very different. Just like with the X-axis, movement along the Y-axis has sub-pixels, but how quickly those sub-pixels change depends on your current “Gravity”, which changes based on “Sub-Gravity”. Your current G determines how quickly your sub-Y changes, according to a table. For G values less than 64 the change to sub-Y is negative (rising up the screen), becoming 0 around 64 (hovering), then beginning to become positive when beyond 64 (falling down the screen). G caps out at 127 (aka “terminal velocity”). Whenever Jack jumps, both G and sub-G set to 0, while hovering causes G to set to 64 and sub-G to 0. Each frame during jump/hover (including the frame of the jump/hover input) will cause sub-G to grow by 240 unless there are up/down inputs. Up inputs make is grow only 160, while down inputs make it grow 352 (aka 1 G + 96 sub-G). Whenever Jack lands on a surface, the main Y value “snaps” to a number determined by the surface, but the sub-Y when landing can be different. With careful input control this can be used to set up for faster jumps/falls. Sub-Y and Sub-G carry over from the end of one stage to the beginning of the next, so you can manipulate inputs when approaching an exit to set up for an ideal start on the next stage.
PALACE ROOM WARPING There are 16 Palace Rooms in MBJ, each with a different configuration of 24 bombs and thin columns/platforms. When the first bomb is collected, another bomb becomes lit determined by a bomb sequence. To warp to the next Palace Room and bypass the labyrinth areas between them, the lit bomb must be collected last. The routes used in each of these stages selects a first/last bomb set that allows for a faster overall path through the room. Ideally we want to collect a bomb near the entrance that will light a bomb near the exit, but the bomb sequence usually doesn't allow this. If the lit bomb is collected early, another bomb becomes lit and the warp will fail. The warp is failed on purpose in PR 4 of this TAS to access a shortcut through the labyrinth.
SPAWN TYPE MANIPULATION Every time Jack jumps or hovers, a counter goes up. When a mummy hits the floor of a room, it will transform into one of six different types of creature. The type of creature is determined by the jump counter's value (mod 6). Usually this doesn't matter in the TAS, but there are a few places where the wrong type of spawn would get in the way.
LAG REDUCTION When too much stuff is on screen and/or happening at once, it's possible for a lag frame to occur which essentially causes the game to freeze for a frame. This is more common on later stages because the mummies spawn faster so you're more likely to have 4 mummies/creatures on screen at once. Also the 20th bomb collected in each stage cause a Power Ball to spawn, and every time you hit a 5000 point threshold a Bonus Coin appears, adding more sprites to the mix. It would be great if points could be manipulated so that those 5k thresholds only occur during the stage clear screens and we never get any Bonus Coins. Unfortunately, options for manipulating points are limited given the fact that our primary goal in this TAS is speed. During stages the only way to adjust points is collecting the Bonus Coin for more points, collecting the Power Ball to turn enemies into coins and collecting the coins, or jumping off a surface which earns a mere 10 points. It's much easier to adjust points during the beginning screen and during the shortcut by collecting more/less bombs and jumping off surfaces more/less. The current version of the TAS had a very good level of lag reduction. Only 5 lag frames, one of which is cause by the presence of a Bonus Coin, and one of which is cause by collecting a Power Ball than can't be avoided without losing more frames than the lag. The other 3 frames are caused my mummies and seem to be unavoidable. Other point alternatives I've tried have resulted in the same or more lag.
MUMMY PHASING Sometimes mummies can pass throw a platform or wall that is supposed to stop them. I don't understand the mechanics of how this is possible, but Jack's X position is clearly an important factor. This version of the TAS has no mummy phasing because the rooms where it was done on purpose have been bypassed by the shortcut, but I still wanted to mention it here for posterity (see previous TAS versions). In both cases I had to “wiggle” Jack while he was in midair to get the mummies to fall completely through the floor. It seems to be a multi-frame process because there can be situations where the mummies look like they're starting to phase through the platform, but snap back up to the surface unless you do the wiggle.
GENERAL TACTICS Below is a list of tactics that I will reference in my stage breakdowns.
  • Corner Clipping: At the right speed/angle, it's possible to make Jack clip into the side of a platform or a chest. This can be useful in situations where a platform is in the way of a desired horizontal movement, effectively shortening the length of the platform, or when a chest would otherwise get in the way of landing and jumping sooner.
  • Clip-Up: When corner clipping upwards, a jump input can be used to make Jack's sprite shift up to get on top of the platform faster than letting him rise normally.
  • Jump Boosting: Stopping at a platform during an ascent to jump off it for an overall faster ascent. This is often after a Clip-up. Clip-ups and jump boosts can be done with consecutive inputs in Palace Rooms because both A and B do the same thing. In other types of rooms B is used to activate Mighty Coins.
  • First Frame Jump: On the first frame that inputs can affect Jack in a stage, a jump input will cause him to jump mid-air from his starting position. After that frame you can only hover when in mid-air.
  • Edge Bumping: When Jack is falling/rising past a platform, there is a particular frame where pressing into the platform will result in on overall sooner horizontal movement, even though the sprite looks like it's facing the wrong direction for a frame.
  • Hisatoki Leap: Developed by Hisatoki in their “Best Ending” TAS, this involves jumping off a platform in order to to fall past its edge faster than hovering over the platform would have been.
  • Pause Jumping: Developed by Threecreepio, this is useful in stages other than Palace Rooms. There are a few places where we must jump off something to break/reveal/open it, then land again as quickly as possible, probably to do it again. Without pause jumping, this would require an A press, a gap frame, and then another A press. But Threecreepio discovered that you can do an A press, start on the next frame, gap frame, then press A and start on the same frame. It would seem that this wouldn't be faster since it takes 4 frames instead of 3, but the pause stops Jack's sprite from getting higher up before the hover.


ROUTE ORIGIN: My stage breakdowns will start with me giving credit to the first usage of the routes. This credit won't necessarily reflect where I myself learned the routing from (I based my early work on Msm_smtn's WR before looking at pre-existing TASes and former WRs), but is intended to give credit to the first person who developed the routing. In the interest of saving time I will only take into consideration 6 sources: Guybrush's canceled 'Any Ending' TAS, Hisatoki's accepted 'Best Ending' TAS, Ktwo's former WR, Msm_smtn's current WR, Procyon's notes, and my own developments. If I give credit to one of these 6 sources, but evidence can be produced that a route was first developed by a different person, I am willing to edit these notes to more accurately reflect that history. Palace Room routes are evaluated on three general elements: the first/last bomb choice, the order the bombs are collected, and the path followed to collect the bombs. If all three elements were developed by the same source, I consider that the same route overall, otherwise I'll specify when the individual elements were developed.
EXPLANATION: In this section I will describe the various TAS tactics used during the route and try to explain why things are done in a certain way. It will not be a full explanation of the route, just the TAS tactics that made the route faster. I will also try to give possible explanations for any lag frames remaining, but I forgot exactly where all the lag frames I was able to avoid are. I won't bother going into detail about the sub-pixel manipulations because almost every jump and up/down input are part of that. The general explanation of sub-pixels given above should be enough to understand those decisions.
ROUTE ORIGIN: Used the No Coin strategy by Guybrush.
EXPLANATION: In terms of speed the only thing that matters on this screen is to keep moving right without stopping or hitting any objects. The TAS reaches the exit as quickly as is possible because Jack does not stop to collect any of the Mighty Coins, even though I do reveal the location of 5 Mighty Coins for the benefit of RTA runners watching the TAS.
ROUTE ORIGIN: Same first/last and bomb order as Ktwo, but Msm_smtn jumped onto the lower left platform after collecting the first three bombs and my path to the first bomb is different.
EXPLANATION: We start by falling down and to the right. Right movement has to be delayed a bit to avoid hitting the upper left platform. As Jack approaches the lower left platform we move left to corner clip into it and collect the first bomb. Without the corner clip we would either collect the bomb to the right first, or be forced to hover to make sure we get the correct first bomb. As we collect the last bomb in the left column we move right to corner clip into the upper left platform, then clip-up and jump boost off it. Another clip-up and jump boost is used near the end of the room as well.
ROUTE ORIGIN: Same first/last and bomb order as Hisatoki, but my path to the first bomb is different.
EXPLANATION: We start off with a first frame jump to go over the bombs to the right before dropping down to collect the intended first bomb. Without the FFJ we would have to tap left to avoid grabbing the bomb right next to us at the start, then hover below the bombs while moving right, which would get us to the first bomb 5 frames slower. After collecting the bottom left set of bombs we jump up and clip into the next platform. A single right input is needed to collect the right bomb of the set before clipping up and collecting the rest of the set. Then we jump up to get to the next set, but this time we don't have the space need to clip (unless we move further right first but that would have taken more time). Instead we do an edge bump while rising past the platform to get us to the left bomb sooner and start dropping down to the platform. The right movement as we're falling has to be delayed a frame or else we would miss the platform. Nothing particularly special after that as far as TAS tech is concerned.
ROUTE ORIGIN: Same first/last as Hisatoki, but I collect one bomb early.
EXPLANATION: After collecting the first bomb, we jump up to the left and clip into the lower left platform, clip up, and move left a little to collect a bomb before continuing up to the left column of bombs. This may seem slower then just jumping up for the column first, but when we come back down to get the other two bombs we're able to jump up sooner than if we had to walk across the whole platform for all three bombs. When jumping to the right side, there seems to be a mummy in our way, but the timing and hitboxes are just right for us to land and jump over it to collect the two bombs on that platform then jump again for the top right bombs. To get from the last platform to the last two bombs, we perform a Hisatoki Leap. This gets us to the floor faster than dropping off the platform or hovering over it.
ROUTE ORIGIN: Same general pathing as Guybrush, but this TAS fails the warp in order to access the shortcut so first/last and bomb order are different.
EXPLANATION: After collecting the bombs on the left floor, we clip into the lower left platform a little bit, clip-up, and jump boost off. The jump boost is performed a little slower than is possible so that we can collect the left bomb on the platform a little early. Like in the last stage, this makes is so that we don't have to walk across the platform as much later and can jump up earlier. We clip into the upper left platform, but have to make a single input move to the left to collect a bomb before clipping up and collecting the rest. Just like in the last stage, a mummy looks like it will be in our way but we have just enough room to land and jump over its hitbox while collecting the bombs on the upper right platform. This ends up being a Hisatoki Leap since we don't have ceiling bombs to grab before going down like in the last stage. Another Hisatoki Leap is performed on the lower right platform.
ROUTE ORIGIN: Described by Procyon in his notes.
EXPLANATION: The first room of the shortcut is vertical and starts off with a first frame jump followed by a series of jump boosts with a couple edge bumps along the way and a corner clip into the chest at the top to jump into the exit sooner. The second room is horizontal and also starts with a FFJ, then up to an edge bump to get moving left sooner. We keep moving left without delay until we get to a platform we have to break to access an invisible chest with a sphinx in it, which will open the door to the next room. Pause jumping is used to get the sphinx faster. We then jump off a platform to the left and head back to the right side of the room without delay, corner clipping into two chests along the way, and jumping up into an exit that's only open because we grabbed the sphinx. In the next room all we have to do is die as quickly as possible. After the death we respawn in the previous room and repeat the sphinx collection and death. (NOTE: the deaths have to occur in the third room). On the third go around we don't die (we would Game Over if we did), instead we FFJ and jump boost our way to an exit in the upper left corner that only appears after the deaths, and corner clip into the chest at the top to jump into the exit sooner. The next room starts off with a FFJ followed by a series of jump boosts. Then the last room of the shortcut is just a FFJ up to the door that takes us to Palace Room 11.
ROUTE ORIGIN: Same first/last as Ktwo's former WR, but bomb order and pathing were developed by Ktwo more recently.
EXPLANATION: The first jump up is technically a clip, but only by necessity since we don't have the space to collect the third bomb and move over to the top of the wall. Hovering over would be slower. We clip in and up at the upper left platform. We don't need the single left input to collect the bomb we miss because we're going back that way again later. We sort of do a mini Hisatoki Leap off the top platform. The ceiling prevents a full leap. Edge bump at the bottom left. We avoid collecting the Power Ball because that would have causes a lag frame. Jump boost on the center right wall, then clip in and up to the upper right platform. The upper right platform looks dangerous because we didn't warp here, which slowed down the mummy spawn timers compared to previous TASes, but luckily because of the clip we are able to avoid the mummy's hitbox. Then another mini Hisatoki Leap to head down to the last bomb.
ROUTE ORIGIN: Same route as Hisatoki. Guybrush's route was very similar, but had a different first/last.
EXPLANATION: Not much here in terms of special TAS tech. We start off with a First Frame Jump in order to get over the upper left bombs and get some of the upper right bombs first. Hisatoki Leap off the left side. Lag frame caused by the appearance of the Power Ball (Bonus Coin being present likely a factor).
ROUTE ORIGIN: Developed by me in 2020 for RTA spawn manipulation purposes, turned out to be good for TAS as well.
EXPLANATION: As far as TAS tech is concerned, there's a clip when going down the right side, then and edge bump near the bottom. Clipping up the left side too, and a clip-up at the top. Likely was some jump/hovers control for spawn type manipulation in there somewhere.
ROUTE ORIGIN: Same route as Hisatoki.
EXPLANATION: No special TAS tech to point out. There's a lag frame from when the fourth mummy spawns.
ROUTE ORIGIN: Same route as Hisatoki.
EXPLANATION: Jump boost off the right wall. Lag frame caused by the 4th mummy spawning, and another by collecting the Power Ball. Deliberately no Jump boost off the left wall at the end because it would be one frame slower.
ROUTE ORIGIN: First/last is mostly irrelevant here since we aren't warping, but pathing was developed by Msm_smtn. I collect one bomb earlier than Msm_smtn, although they may have skipped it by mistake.
EXPLANATION: We do a First Frame Jump so we can get the top left bomb and immediately hover so we get the second too (in hindsight this isn't necessary since collecting them at the end wouldn't slow down our approach to the exit, but it's a helpful thing to do in RTA since it makes it easier to hit the exit). Clip in and up when entering the bottom hole. Also clip on the way out. Lag frame when fourth mummy spawns.
ROUTE ORIGIN: No coin strategy from Guybrush.
EXPLANATION: We start with a first frame jump up to the platform. Edge bump on the way up. Pause Jumping to break the blocks. Didn't need pause jump when opening the chest, doing the regular double jump was just as fast for some reason (does need different sub-pixel manips afterwards though). Rightward movement to the exit needed to be stopped for one frame to avoid hitting the platform. In the second room, there is technically a clip-up to get on top of the invisible chest. Pause jumps to reveal chest and open it. When we return to the first room, we edge bump and jump boost to get to the exit faster. In the last room, we FFJ to get up faster. Hisatoki Leap to get down faster. Pause jumping to break blocks faster. Edge bump and jump boost to the exit.


For anyone who's interested, here's a TAS with 37 frames of improvement compared to my previously published submission, just in case anyone was interested in the fastest possible "Deathless" route. It uses a new route for PR 9 with a different first/last bomb.

nymx: Claiming for judging.
nymx: Corrected the name of the game from "Might" to "Mighty"
nymx: Great job on improving this run. This reminds me of when I went a little deeper, on my re-TAS of Krusty's Super Funhouse. I find it amazing how all these cuts elude RTA game play. its only when you step through a game, frame-by-frame...that you'll start seeing things that no one would have ever considered.
Everything seems to be fine here.
fsvgm777: Processing.

Joined: 8/3/2004
Posts: 14951
This topic is for the purpose of discussing #8559: SpaceColonizer's NES Mighty Bomb Jack in 06:01.39
Player (244)
Joined: 8/10/2008
Posts: 113
The "new" shortcut is a really cool finding! Good job going through the resources again for this game and picking up on this secret that had been overlooked until now (at least by speedrunners). The shortcut itself is one of those "impossible" secrets that I wonder if anyone managed to find legimately on their own by just playing the vanilla game and equipped with the manual, but without exploring save states or looking at the RAM or in the code. I guess we'll never know, but I'd be very interested to hear what the developers for this game and Solomon's Key had in mind with some of the overly obscure secrets. Maybe the sole purpose was to sell guide books? About the TAS itself. The new TAS looked the same as the previous one up until palace room (PR) 4 and then the same again from PR 12 until the end. PR 4 and 11 play out slightly differently this time around because of the shortcut, but the changes made sense to me. The shortcut traverses the level 5 corridors and the end of the last level 10 corridor ( ). There are some routing decisions when going through these corridors and which platforms to jump to (shorter jump now and then a bigger jump or bigger jump first and then a shorter jump?). I checked one of those cases, but couldn't find an improvement by taking the alternative route. The game mechanics are not trivial when testing, so I didn't check all of the alternative routes. In the end, nothing stands out to me as questionable, just noting that there are sometimes route alternatives that are not obviously slower just from watching. A question that came to mind when hearing about this shortcut was if the conditions were really exactly as described or if a different setup could be found. This sub-routine runs in corridor 5-5 (with reference to the room numbers in the link above):
A8E9  LDA $0396 = #$00
A8EC  BNE $A925
A8EE  LDA $0395 = #$00
A8F1  CMP #$02
A8F3  BNE $A907
A907  LDA $03CE = #$E9
A90A  BPL $A925
A90C  LDA $0392 = #$5D
A90F  CMP #$5D
A911  BNE $A925
A913  INC $0392 = #$5D
A916  INC $0395 = #$00
$396 - unknown purpose $395 - death counter in corridor 5-5 $3CE - MBJ status flag $392 - room-specific death event "trigger"? The first four bits in $3CE indicate whether MBJ is alive (0) or dead (0xE). The last four bits don't matter for this sub-routine, but indicate whether he's on the ground or in the air (only a quick check, so maybe there are other possibilities too?). So in the example above, MBJ just died. I didn't look into $392 in detail, but it's set when dying in corridor 5-5, which allows the check in the sub-routine to be passed. If I remember correctly, there are other secrets that require deaths in this game. Maybe this address is used for them as well? Each time you die in 5-5, $395 is increased by one and when it's counted up to 2, the sub-routine branches and $3BC changes value, which opens the (ultra-)secret passage to 5-X. So let's get back to how this fits with the setup described for this shortcut: 1. Collect the sphinx in 5-2 - This opens up the passage to 5-5. There is no other known way to open up this passage. 2. Enter 5-5 3. Die in the fire pit - There are no enemies spawning in this room, so the only way to die is in the fire pit (or maybe by letting the time run out?). Dying in 5-5 increases the value in $395 and the sub-routine that increases $395 only runs in 5-5 (at least of the rooms visited in this TAS). The only other times the value in $395 is updated during the TAS is after clearing a PR and then it's to reset its value to 0. So maybe this address is used for other secrets as well and resetting it after each PR ensures that you don't start triggering a secret in one level and then trigger a secret in another level earlier than intended? 4. Repeat 1-3 5. Repeat 1 and 2 6. Enter the passage to 5-X Without a deeper analysis, it's of course always possible that one can access the relevant code sections through different parts of the code, opening up new possibilities. But as far as I can tell and with today's knowledge, the code seems to support that the steps in the described setup are indeed required to open up the shortcut.
Editor, Expert player (3551)
Joined: 11/30/2014
Posts: 2744
Location: US
Cool and very obscure new discovery, nice. I wonder how many other games have stuff like this? I managed to console verify this (I used BizHawk which has one less lag frame at the start but is otherwise identical.) Link to video
Post subject: Movie published
Joined: 8/3/2004
Posts: 14951
This movie has been published. The posts before this message apply to the submission, and posts after this message apply to the published movie. ---- [5525] NES Mighty Bomb Jack by SpaceColonizer in 06:01.39