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This thread for the weird game. Looks that the ship can shoot at 3 directions at the same time.
Here, my YouTube channel: http://www.youtube.com/user/dekutony
Post subject: Re: Vanguard
Spikestuff
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Kurabupengin wrote:
Looks that the ship can shoot at 3 directions at the same time.
Incorrect. By holding a direction then shooting you can shoot one way. By switching another way very quickly you can shoot two ways. You ALWAYS shoot forward. Holding backwards and shooting you can obviously shoot backwards.
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Ford
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Finally home from work, so now I can discuss this: I'm new to making these videos, so I decided to use this short game for practice. hegyak said I should probably come to this thread to discuss it, so here I am. So, I'm not exactly sure what to say or ask, but...well, while I think the movie looks fairly good, I'm sure it can be done better. The Styx Zone in particular bugs me: I tried several times, but two of those jet-like enemies still managed to NOT get asploded. Should I find a way to asplode them anyway, or would it be better to make it look like I completely disregard them, or what? Also, any idea how the RNG works? From the little testing I've done, it looks like it can be advanced by starting the game on a different frame, but starting the game on any frame other than the first frame locks the game into a demo state for over 200 seconds, which would seem to completely negate any benefit from luck manipulation from the machine turn-on. Perhaps luck can also be manipulated by a level on a different frame? Should I also make an effort to do the second tunnel as well? The order of the phases is different and the game scrolls faster, but effectively it's all precisely the same material, leaving me to wonder if anyone would even find that entertaining. I also refused to touch any of those energy pod dealies, as missiles fly far faster than the ship does, thus making shooting the preferred option for destroying enemies over turning one's ship into a rave and blasting Vultan's theme at a volume level of 11. I'm really new to all of this and I would greatly appreciate any advice or insight anyone is willing to offer me. Thanks. EDIT: I began playing around with the RAM watch. I found the score addresses at 0x17, 0x18, and 0x19 (didn't bother to check 0x1A). I then poked them a bit and found that they had no bearing on whether or not the player progresses to the next round. On a hunch, I began looking for values that decreased. I found one at 0x35 that decreases each time you score a kill. With the exception of the "boss," the game appears to allow you to move on to the next phase under the following conditions:
    1: 0x35 must be greater than 127 (this also halts enemy respawns) 2: The screen must be clear of all enemies and pods
I also discovered that 0x16 counts every frame less lag frames. I tried freezing the address, and the screen pretty much stopped scrolling, energy completely stopped depleting, and enemies completely stopped spawning. From my observations, it appears the player is allowed to move any time this address is even, and the playfield scrolls by one tile in the first tunnel any time the address is equal to (a multiple of 8) + 1. I'm starting to research enemy respawns. As progress through the game hinges entirely on killing enemies, understanding the rules that dictate when they respawn is crucial to an efficient TAS of this game. EDIT 2: They spawn in waves roughly once every 64 frames. With this new information I've found, I feel confident that I can redo this TAS and make it better. I'm already seeing a gain of at least two seconds in the Mountain Zone.
Ford
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Sorry about the double post, but I need some help here. I finally found the address for the player's X position at 4F, but it is weird. Moving the player from the far left side of the screen towards the right, the address shows these values in the following sequence: 11, 01, f1, e1, d1, c1, b1, a1, 91, 72, 62, 52, 42, 32, 22, 12, 02, f2, e2, d2, c2, b2, a2, 92, 73, 63, 53, and so on, all the way up to aa at the far right of the screen. As you may be able to see, the left nibble actually descends as the player goes to the right, whereas the right nibble is treated as the upper nibble and ascends as the player goes to the right. The left nibble also skips the number 8, and the right nibble increments every time the left nibble hits 9. Is there a way I can view this information in a more meaningful way? I'd like to be able to view it from a more traditional sort of view, much like the well-behaved Y position at 5C. Moreover, this is one of the many ROMs that Bizhawk appears to be emulating incorrectly, as the player's visible X location on the screen skips a number of pixels near the left side of the screen. I am fairly certain this does not happen on a regular console, and a number of different a26 ROMs behave in this same, odd fashion. Should I just wait for Bizhawk to receive an update that corrects this? Conceivably, it wouldn't be an issue for the Mountain Zone or the Sticks Zone, as I don't intend to leave any survivors that could cross that point, nor for the City of Mystery or Gondor, as everything either moves vertically or never reaches that point of the screen. It might become an issue in the Rainbow Zones that regularly move sprites horizontally across that region of the screen, or the Stripe Zone if sprites there actually do (I don't rightly remember). While a TAS could be made, I wonder if it would desync in a later version of Bizhawk that does not experience this problem.
Ford
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Link to video Finally got around to doing more work on this. I finished the Mountain Zone and the first Rainbow Zone. I'm making some headway, but this game is giving me a share of frustration and concern. My primary source of frustration stems in part from the way the game determines whether or not you have progressed to the next phase. To progress to the next phase, you must underflow the kill counter and clear the screen of enemy sprites. In the Mountain Zone, the first phase has Mist Ships. Kill counter is set to 16, so you must destroy at least 17 Mist Ships to progress to the next phase. It is then set to 24, and Harley Missiles begin spawning, so you must destroy at least 25 of them to move on to the Rainbow Zone. Deal is, the Mountain Zone also spawns Energy Pods (which ALSO count as "enemy" sprites) at regular intervals, and the damn things keep spawning JUST before I manage to score the target number of kills, forcing me to wait until the pod scoots off the screen before the next phase begins. I tried, but for the life of me, I can't figure out a means to beat either of the pods to the next phase. I'm not too worried about the first one; it spawns so early that I've written off beating it to the next phase as impossible, but the second one is so tantalizingly close! I'm also a little worried that my run through the Rainbow Zone might not be optimized. I dunno, maybe I'm worrying needlessly. I'll try toying around with that area a bit more to see if I can improve it, but what do the rest of you think?
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I am not at all familiar with this game, but have you tried collecting the energy pod to get rid of it?
Ford
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Scepheo wrote:
I am not at all familiar with this game, but have you tried collecting the energy pod to get rid of it?
I appreciate the suggestion, but touching an energy pod does not remove it. If you're curious, touching the energy pod has the following effects:
    Invincible: destroy enemies on collision. Intangible: can move through solid objects. Refuel: upon leaving this state, the ship is fully refueled. No shots: the ship cannot fire missiles in this state.
Because killing enemies restores a single unit of fuel, and because I can destroy ships faster than my fuel depletes during frame-by-frame play with rerecords, the refueling aspect of the energy pod does not give sufficient incentive for me to touch it. The real nail in the coffin is that it prevents me from firing missiles (my most efficient method of scoring kills). This means that using energy pods actually makes it take MORE time to complete the game instead of less! (The Stripe Zone much later in the game might be an exception; due to how clustered together enemies are, energy pod use there may actually take the same amount of time as conventional missile fire. I'm considering doing that for entertainment purposes later on.) If the energy pod sprites got removed on use, that would be an interesting aspect to consider though. Once again, I sincerely appreciate the suggestion.
Samsara
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Do the pods always spawn on the same frame no matter what, or can they be manipulated? If they're deterministic, you might have to just accept that you can't beat it and work on making the waiting period entertaining.
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Ford
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Samsara wrote:
Do the pods always spawn on the same frame no matter what, or can they be manipulated? If they're deterministic, you might have to just accept that you can't beat it and work on making the waiting period entertaining.
I might have to go the entertainment route, though my options for entertainment are a little on the thin side. The pods always spawn in specific locations anchored to the automatically scrolling background. The only way to make them spawn later would be to start the game later, offsetting their spawn by an identical number of frames. Unattractively, starting the game any later than frame 1 causes the game to go into a demo from which there is no escape for over 100 frames. In my present run, I already make a feeble attempt at entertainment by vibrating my ship against a wall while I wait for the next phase to begin. I also tried crashing my ship, but it doesn't erase the pod either.
Samsara
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Yeah, it looks like you're gonna have to go the entertainment route. Sometimes you just can't beat determinism. It's the reason why I stopped working on Splatterhouse. I wouldn't stress out too much over how to entertain: Just do what you think is awesome or funny and other people will usually agree.
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warmCabin wrote:
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Ford
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I couldn't really think of much to do for over 150 frames. There's no music my ship could dance to, and only five buttons to press. So I did the Konami code. Or at least what would count as the Konami code with no A or B. Anyhoo, after a long time of not looking at this, I finally started getting back into it. I haven't done much yet - just the Harley part of the Styx Zone twice (once attempting to kill all Harleys and leaving no survivors, and a separate time callously ignoring Harleys at the extreme top and bottom of the screen as warranted in the interest of clearing that phase as quickly as possible. Saved around 50 frames, and finished that phase with five Harleys killed within the space of ten frames.) Did more work on it. I'm now past the second Rainbow Zone, which was pretty fun to do. Next up is the Stripe Zone where randomness doesn't exist. I'm looking forward to the crazy crap I can do there. Stripe Zone. The Stripe Zone now holds the honor of invoking a situation where it was actually faster to crash into the last enemy instead of shooting it - doing so despawned an invincible enemy, allowing me to almost instantly progress to the THIRD FREAKIN' RAINBOW ZONE! For those of you wondering, phases are cleared after reaching the target number of kills. Or more specifically, after the counter underflows. Now, there is one thing I'm wondering, and that's if a proper TAS of this game should include the second tunnel as well as the first. The layout is different, so the map looks considerably different, but all the zones are precisely the same. They are simply in different orders and the playfield moves twice as fast. I kinda doubt the second tunnel would be very interesting after the first tunnel, though maybe I should just for closure, and the viewer can decide for himself whether or not to watch the second tunnel. I'm leaning towards doing the second tunnel, as the game isn't terribly long before it repeats from the beginning, but I'll make that decision after completing the first tunnel and reviewing the resulting video. I reached a decision: I will do the second tunnel as well. There are aspects about the phases in the second tunnel that are completely absent from the first, so I feel it will be interesting enough to watch.
Ford
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Finally through the entire first tunnel. I'm not done yet. I feel that any TAS of Vanguard that does not do both the first and second tunnel is an incomplete TAS. While the second tunnel has the same phases and enemies as the first tunnel, they are in a different order, the scroll speed is doubled, and some enemies fire missiles that didn't before. Besides, the first tunnel only took like 2:36 to complete; how much longer could the second tunnel possibly take? I wound up using death to save time twice: once in the Stripe Zone (to despawn the invincible Floating Payne and make the next zone load sooner), and once to Gond in the City of Mystery (you don't need to kill him to proceed, and the fireworks take longer than simply dying). Link to video Since I've reached a major milestone in this movie, I would REALLY appreciate feedback. Please?
Spikestuff
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Ford wrote:
I'm not done yet. I feel that any TAS of Vanguard that does not do both the first and second tunnel is an incomplete TAS.
If there is no difference between first and second then don't do second, if there is then do second. Anyways, looks as it should. Crap. Loved the damage abuse but too bad I couldn't see your final shot due to the video being cut off early.
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Ford
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Well, the second tunnel scrolls the zones at double speed. As I had to do go to certain lengths to score some kills, I anticipate the second tunnel will require different tactics. Also, in the second tunnel, the Romedas (the bomb-lookin' things near the boss) will actually fire missiles to the side. If the gameplay for the second tunnel doesn't offer sufficient variety from the first, I can always cut off all input immediately before encountering the boss in the first tunnel (oddly enough, absolutely no input is required to beat him). The final shot, btw, was basically me flying directly into an enemy missile and dying, thus starting tunnel 2 earlier than killing Gond would have.
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Yeah, I'd say go for the second tunnel for now, as you can always cut it off later. Good research on the method for progressing in this game by the way, A2600 games can be tricky with that.
Ford
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So after like an eternity of not doing anything with this, I notice that BizHawk 1.11.7 has updates to the A2600 emulation. I couldn't be happier about this. The older versions, I had noticed, are horrendous at emulating Atari games, with some of them exhibiting atrocious bugs that never existed in the console version (and yes, I'm old enough to remember the console versions). I decided to upgrade and see if my old movie synched up. It did not. To be honest, I'm not upset about this at all, as I had recently discovered a trick that allows me to shave two to three seconds off my TAS, though it also completely throws off the RNG, resulting in a huge desynch even if I modify the input file for the offset. Details on the trick: In Vanguard, if you do not press any buttons at all on the very first frame to start the game, on the very second frame, the game launches into a demo. This demo is completely unskippable for about five seconds, thus forcing us to start the game immediately by pressing the fire button on the very first frame. This also completely prevents RNG manipulation. Or so I thought. As it turns out, pressing Select and Reset on the same frame skips the map screen on the demo. Two frames later, pressing Select and Reset again forces the game to immediately start. This means that not only can I completely skip the map screen on the normal game start, I can also start the game whenever I damn so please, and in doing so, also possibly manipulate luck. I doubt this is exactly intentional behavior on the game's part, and rather the nature of the beast that is Atari 2600, over which the programmer(s) likely had no control. Moreover, I also discovered something I had forgotten about this game when I was initially playing it 30 years ago: it turns out the difficulty switches actually DO SOMETHING! They don't modify the difficulty, though; they're merely settings for how the ship's firing works. I don't rightly recall which setting does which, but one of them toggles whether the ship always fires forward or not, and the other toggles whether holding the fire button down causes the ship to fire or hold fire. The former conceivably has some effect on the speed with which the game can be completed, allowing you to not fire forward when you won't hit something (you can only fire one missile forward at a time). The latter has no bearing on completing the game quickly at all, and is merely a matter of preference. I got my work cut out for me. I'm just glad it's not a very long game.
Lord_Tom
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Was just thinking of this game the past few days and happened upon this thread. I like the WIP; it's great that stage progression works as it does as it gives a sizable advantage to TAS which wouldn't necessarily be found in an autoscrolling game like this. For the extra seconds related to the energy pod it is what it is; since there aren't really great entertainment options you could think about spacing out your kills (maybe even touching the pod to kill a few enemies) so you get the final kill just as the pod despawns. I definitely agree with doing the 2nd tunnel, especially with how short this'll end up being. Do I vaguely recall there's some benefit to crashing into the ring-shaped wormy creatures in one of the later stages? It's been 30 years so memory's a bit foggy...;)
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From the Vanguard manual "Kemlus snakes fly out of the rocks and attempt to crush your spaceship. Normally you shoot Kemlus, but if you can maneuver your spaceship into the center of a Kemlus and dock with it (touch it), you can get a free ride and earn losts of bonus points without being crushed. Kemlus are not very bright, but they figure this out after the third ride, so don't try for a fourth ride. Kemlus revive if you touch them right after shooting them. This means you can shoot a Kemlus and then dock with it to earn extra points. After the third docking, however, touching a Kemlus after shooting it is certain death."
Ford
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Score-wise, flying into Kemlus is a fantastic idea. Speed-wise, it is a terrible idea. Flying into the first three gives you a large score bonus (any others later on just crash your ship). Deal is, this results in a sizeable animation freeze. In a TAS that is focused purely on speed, this animation freeze is a complete antithesis to the goal of the run. It might be fun for a run that "contains speed/entertainment tradeoffs," as well as one that actually uses energy pods. That said, I have to wonder if the two runs would be different enough to warrant their individual existences.