(Link to video)
Night Stalker is a top-down maze shooter released in 1982 for the Mattel Intellivision. You are trapped in a maze while robots, spiders, and bats relentlessly track you down. The key to survival is to destroy as many of them as possible -- before they get you!
While the robots only spawn in the lower left corner of the map, the player is normally given an incentive to wander throughout the maze when ammo spawns in a far away location. TheWinslinator and SuperMonkeypotato make the game look too easy by manipulating ammo to also only spawn in the lower left corner for the fastest robot massacre in history! The robots aren't shown any mercy once an Invisible Robot is killed, which appears after 80,000 points is reached, and marks all of the game's content being showcased.
Objectives
  • Uses hardest difficulty
  • Uses two controllers
  • Heavy luck manipulation
  • Genre: Action/Shooter
General Information
  • Game speed does not increase as you play Night Stalker, unlike most Intellivision games.
  • Spider, bat, and gray robot movement is random. All other enemies seek the player.
  • RNG can be manipulated by the timing and direction of the player's shots.
  • Normally, you cannot run and shoot at the same time, but using two controllers (one for running, one for shooting) resolves this issue.
  • Only two bullets can be in the maze at once: one from the player and one from enemy robots.
  • Bullets can be shot at four different vertical positions in the corridor where the robots spawn.
  • Collision detection in this game is extremely accurate, so you need to take all subtleties in enemy/cave geometry into account to save frames. For example, aiming at height 1 (see figure) kills this robot the fastest, but aiming at height 2 despawns the bullet quicker. Each are due to the robot/cave geometry jutting out slightly farther than the other heights.
Ammunition You get bullets by collecting guns which can spawn in five locations throughout the maze (see diagram below). Each gun gives you six bullets, and the location of the next gun spawn is determined by the frame your sixth bullet shot despawns. With the exception of the first gun, we manipulate the gun to always appear in the lower left corner so we can immediately wreck any robot which spawns. This gun spawn manipulation is the most significant source of timesave over any RTA run.
Points Table Spider = 100 | Bat = 300 | Gray Robot = 300 | Blue Robot = 500 | White Robot = 1000 | Black Robot = 2000 | Invisible Robot = 4000
The Spider He sticks around the entire game and is only worth 100 points so we ignore him most of the time, unless we have to wait a while for the next robot to spawn.
0 - 4900 points 1 gray, 2 bats. We have two options for this segment: go right and kill some bats, or go left and focus on the gray robot and spider. While initially it may seem faster to grind for points on the bats, their longer respawn time and the HUGE walking distance you will need to make to the lower left corner when 5000 points is reached makes that option unoptimal. So, we instead focus on the gray robot and spider. However, at 5000 points, gray robots will spawn in place of the bats. For this reason, we need to kill the bats as we cross this threshold. Both bats were manipulated to a location where they could be easily shot by the player and gray robot.
5000 - 14900 points 1 blue, 2 gray. Now that a bunch of robots are spawning in the lower left corner, our rate of point increase skyrockets; but we run into a new issue: a glitch which we will refer to as "phantom shots". When destroying these new gray robots on the first frame they spawn, bullets will randomly shoot at you from thin air! We believe this is due to the game calculating the destroyed robot's projected path, and shooting bullets from those positions. The phantom robot appears to "die" when its gray counterpart spawns again.
15000 - 29900 points 1 white, 2 gray. The white robot takes three hits to kill as opposed to one. Not much changes in terms of strategy.
30000 - 79900 points 1 black, 2 gray. By this time, both gray robots have been manipulated to spawn simultaneously for much easier shooting. The black robot shoots gigantic "energy bolts" which neutralize the player's bullets if they touch. Luckily, there is a single pixel above the bolt which we can slip bullets by, so this isn't much of an issue. At 50000 points, the energy bolts change color from white to yellow. These new bolts are capable of destroying the bunker in the center of the map.
You can sometimes be awarded 2300 points for destroying a black robot (and rarely, 1300 for a white one). As of this moment, we have no idea why this happens. However, we do know that having other sprites (energy bolts, other robots) nearby, and walking upwards as the robot is destroyed can increase the chance of getting the bonus. Through trial and error, we get as many of these kills when optimal.
80000+ points 1 invisible, 2 gray. The invisible robot is the last robot type. Well... he isn't technically invisible, just assigned the exact same blue color as the background. Otherwise, he's identical to the black robot. His death marks all of the game's content being showcased.
I'd like to thank SuperMonkeypotato (SMP) for some of the techniques used in this TAS, special assistance, and allowing this project to finish in a timely manner. He will also be helping me in our next TAS, AD&D: Treasure of Tarmin, so I look forward to working with him again. I'd also like to give shoutouts to baldnate and Intellivision Master for their competition towards bringing down the RTA 80,000 Points time!
Suggested publication notes Just go ahead and copy/paste the first two paragraphs.
Suggested Screenshot Frame 2949

Memory: Judging
Memory: Updating with file that defeats the invisible robot.
Memory: Aside from potentially looking further into what causes some robots to give more points at times, this appears to be as optimized as it gets.
With the movie now defeating the invisible robot, it can be considered to complete all new content. The rules have been updated to clarify that the new content is to be completed, not just spawned in.
The movie received much mixed response. While some responses were positive, the rest of it was fairly negative. The movie is very repetitive, without much variation therein.
Accepting to Vault.
fsvgm777: Processing.

TASVideoAgent
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EZGames69
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I have no idea what's going on, but I guess that's normal for intellivision games. Looks very optimized, and I like it when you shoot multiple enemies at once. Unfortunately it gets pretty repetitive. Overall a Meh vote.
[14:15] <feos> WinDOES what DOSn't 12:33:44 PM <Mothrayas> "I got an oof with my game!" Mothrayas Today at 12:22: <Colin> thank you for supporting noble causes such as my feet MemoryTAS Today at 11:55 AM: you wouldn't know beauty if it slapped you in the face with a giant fish [Today at 4:51 PM] Mothrayas: although if you like your own tweets that's the online equivalent of sniffing your own farts and probably tells a lot about you as a person MemoryTAS Today at 7:01 PM: But I exert big staff energy honestly lol Samsara Today at 1:20 PM: wouldn't ACE in a real life TAS just stand for Actually Cease Existing
Twisted_Eye
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oh MAN I put *hours* into this game when I was a child, and you get to the final robot in 3 minutes? Damn, I shouldn't have questioned how cool a TAS of this would be when I was looking at the INTV library. The constantly exploding robot parts made this entertaining to me, especially with how it was so nonstop that the "music" can't even play at all after the first few seconds. I gave this a Yes vote, with noted nostalgia bias. Good vid!
mklip2001
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This is an example of a game where the optimization and manipulation is impressive, and the effects are pretty good for Intellivision, but the gameplay is unfortunately very repetitive to someone who doesn't know the game. For that reason, I had to vote No on entertainment. Good job though!
Used to be a frequent submissions commenter. My new computer has had some issues running emulators, so I've been here more sporadically. Still haven't gotten around to actually TASing yet... I was going to improve Kid Dracula for GB. It seems I was beaten to it, though, with a recent awesome run by Hetfield90 and StarvinStruthers. (http://tasvideos.org/2928M.html.) Thanks to goofydylan8 for running Gargoyle's Quest 2 because I mentioned the game! (http://tasvideos.org/2001M.html) Thanks to feos and MESHUGGAH for taking up runs of Duck Tales 2 because of my old signature! Thanks also to Samsara for finishing a Treasure Master run. From the submission comments:
Shoutouts and thanks to mklip2001 for arguably being the nicest and most supportive person on the forums.
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This run looks really optimized. I like the strategy you used here. It's not the most entertaining game, but I don't have high expectations for Intellivision games. Overall, I vote yes.
Alyosha
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Hitboxes in this game are actually extremely accurate
I think it's worth noting here that the Intellivision uses hardware level collision detection (like the A2600.) So, there are no hitboxes like you encounter on the NES for example. If pixels from 2 different objsects overlap, this information is placed on a hardware register. That's why the collision detection is pixel perfect.
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@Alyosha Thanks for the fun fact, I changed the submission notes accordingly
Memory
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I might need some additional clarification to ascertain whether or not the game was truly beaten according to the rules. Is it possible to defeat this "Invisible Robot"?
[16:36:31] <Mothrayas> I have to say this argument about robot drug usage is a lot more fun than whatever else we have been doing in the past two+ hours
[16:08:10] <BenLubar> a TAS is just the limit of a segmented speedrun as the segment length approaches zero
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I would assume so, but I believe it's going for a "no new content exists" aspect rather than a proper "win".
Memory
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Habreno wrote:
I would assume so, but I believe it's going for a "no new content exists" aspect rather than a proper "win".
I wouldn't assume so because collision appears to be based on actual pixel values for intellivision games, see above discussion.
[16:36:31] <Mothrayas> I have to say this argument about robot drug usage is a lot more fun than whatever else we have been doing in the past two+ hours
[16:08:10] <BenLubar> a TAS is just the limit of a segmented speedrun as the segment length approaches zero
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Invisible doesn't necessarily mean it isn't there and you can't interact with it or shoot it, just means you can't see it.
Twisted_Eye
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I believe it's only "invisible" in that it's entirely the same color as the background. There are very brief places in the encode where you can see little bits of its sprite, and it's the same as the previous robot but in the dark blue of the background. So yes: The robot can be killed after three shots, it'll explode, and then respawn, forever repeating without change. ...unless there's some killscreen caused by score overflow or something
Memory
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Can someone please provide evidence that this is indeed the last unique enemy to spawn?
[16:36:31] <Mothrayas> I have to say this argument about robot drug usage is a lot more fun than whatever else we have been doing in the past two+ hours
[16:08:10] <BenLubar> a TAS is just the limit of a segmented speedrun as the segment length approaches zero
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https://www.youtube.com/watch?v=5KCbvy56jfM This is gameplay of someone getting to over 200000 points and there aren't any new enemies. I think that Wins told me there was someone that was able to do something further, I'll ask if he can send that here as well.
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The best way to verify this is looking at the game code where it decides which enemy to spawn.
Warning: When making decisions, I try to collect as much data as possible before actually deciding. I try to abstract away and see the principles behind real world events and people's opinions. I try to generalize them and turn into something clear and reusable. I hate depending on unpredictable and having to make lottery guesses. Any problem can be solved by systems thinking and acting.
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Twisted eye is right. While "Invisible Robot" is the canon name, it's actually just the same color as the background and can be defeated. There is no killscreen in this game, and invisible robots will spawn until 3,276,800 points, after which 1 gray robot and 2 bats will spawn again, indicating the difficulty has reset. Therefore, it is the last unique enemy and adheres to the "no new content appears anymore" rule. The instructions manual also states that he is "the ultimate aggressor": http://www.intellivisiongames.com/bluesky/games/instructions/action/nitestkr.pdf Hopefully this answers your question @Memory
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Okay. The ending. At tasvideos, we don't consider the game reasonably beaten if you just reach some score, even if the game says it's your goal. For games without an ending, we judge by unique content and difficulty. An invisible enemy is difficult in real-time, but trivial in a TAS. Yet it's arguably more difficult than the prior enemies. Also, it's the last unique one. But the thing is, what's the point in spawning the most challenging/last unique enemy if you don't defeat it? The rules don't clearly ask for that, and I guess we need to clarify this, but consider this example: Say we have a game with 100 enemy slots, it spawns them on timer, and you don't have to defeat them to let the new ones spawn. They just spawn, and the game becomes harder with increasing amount of enemies on the screen. And each enemy is a bit harder than the previous. The current rules don't explicitly require to beat any of these enemies. But it doesn't mean that you just have to spawn them all and die, even thought it'd effectively mean "no more unique content is shown". The point of game completion is completing this unique (and/or hardest) content that is provided. I'll clarify this in the rules, but I think it's quite obvious that this last enemy needs to be defeated to say "we completed all that is unique in this endless game". http://tasvideos.org/MovieRules.html#GamesWithoutClearEnding
Warning: When making decisions, I try to collect as much data as possible before actually deciding. I try to abstract away and see the principles behind real world events and people's opinions. I try to generalize them and turn into something clear and reusable. I hate depending on unpredictable and having to make lottery guesses. Any problem can be solved by systems thinking and acting.
Memory
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As a clarification, in order to accept for publication, we would like to see all unique content completed. In this case, that means a movie that defeats the invisible robot. If you can update the movie with one that defeats this invisible robot and upload it to userfiles or something, it would be appreciated.
[16:36:31] <Mothrayas> I have to say this argument about robot drug usage is a lot more fun than whatever else we have been doing in the past two+ hours
[16:08:10] <BenLubar> a TAS is just the limit of a segmented speedrun as the segment length approaches zero
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Okay the movie and submission notes have been edited accordingly. Here's a link to the updated movie file: http://tasvideos.org/userfiles/info/47825352184695207
Post subject: Movie published
TASVideoAgent
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This movie has been published. The posts before this message apply to the submission, and posts after this message apply to the published movie. ---- [3730] INTV Night Stalker by Winslinator & SuperMonkeypotato in 03:09.62