Best experienced in a browser with an Xbox or similar controller

My Pico-8 version of the 1982 Williams arcade classic.


Supports 4 control methods but controller-based twin-sticks are only supported when playing in the browser.

  • Twin Stick
    • If you have an Xbox or similar controller connected, this is THE way to play
    • Keyboard controls are swapped. Arrow keys fire, S F E D move
  • Twin Stick (Swapped)
    • Arrow keys to move, S F E D to fire
  • Auto-Fire
    • Llamatron style controls. Fires in direction of movement but hold X to move without changing the fire direction
  • Auto-Fire (Lynx)
    • Based on the Atari Lynx control system. Z and X rotate direction of fire

WARNING: Binaries will not support twin-stick controller play.

Thanks To

  • Shane R. Monroe (@ShaneRMonroe) for his invaluable advice, testing and feedback
  • Finn for further testing
  • PICO-8 for creating an awesome "fantasy console"

Version History

0.80 - 26-Jan-2022 - Released
0.81 - 31-Jan-2022 - Fixed endless loop bug that could occur in later levels


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roboton.p8.png 41 kB 714 kB 3 MB 2 MB 957 kB


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Thanks for implementing Atari Lynx auto-shooting, and also for remembering the  controller style choice as part of the cart save data! Kudos!

(We implemented that in Argon recently -- if you have an Android/Amazon/Win11 device, DM us on social media (FB/Twitter/IG) and we can set you up!)

Beta 6:

Looking good overall.  The more the sprites change, the worse I do.  I guess that is "visual muscle memory", no?

The "game over" tune and words feel too far apart.  They were more in sync before the Game Over changes.  Intentional?

not intentional. Just a case of me developing with sound off. Easy fix. The hulk and tanks are both slightly smaller now. I’ll check the hit boxes, see if they’re correct. Should be slightly easier if anything 🤔

I'd say good to go on the brains wave!  feels great!  I'd say reset back to wave 1 going forward.

Great. Thank you. I think the "Tank" levels are probably the last to test.

Level 7 onwards. Any feedback on these (apart from the tank sprites which are just placeholders) would be much appreciated.

The tank level may be a tad too easy.  I usually drop a couple of lives on that stage - but pretty much walk through it here.  If you want to pop a build that starts us on the tanks? I'll give it more thought

Thanks. May not be a build for a day or two so if you do have any thoughts, let me know and I'll look at incorporating them if I get the chance.

My biggest concern right now is getting it working on Anbernic :D

Beta 4:

Brain wave feels considerably better!  I might dial the prog conversion up a tiny bit.  Doesn't feel like we're getting enough now .. maybe 50% closer to the original numbers?

Beta 3: 

  • Collisions are MUCH IMPROVED!  Thank you.  Every death (and there are many) seems "fair" now.  To me, that is a HUGE piece of the leveling out of the way.
  • The sound FX helped immensely too.
  • Converted lemmings on brain waves should reset to standard if the player dies.  Right now, they are "progs" at the beginning of a respawn.  This is obviously a creative choice - but these are supposed to almost be "bonus levels" where, if played right, a bonus life is assured.  This change might put it back to feeling a little more like it. :D
  • Thanks for the green lemming (almost should be a red shirt, no? LOL)  I feel there is still an opportunity for tuning though.  Almost like non-green shirts should offer a small random chance of resisting conversion.  I'll ping you on Twitter about this.

Shame, unplayable (outside of autofire) on Anbernic.  I'll throw together a video to show you what's going on.  Anbernic is really popular -- probably worth its own control scheme if necessary :D

Beta 2:

Excellent improvements all around!  Able to get past wave 10 relatively easily without those cheap enforcer shots :D

The enforcer spawner balls ... is the collision detection based on the actual size of the pulse at the moment or is it based on the full size of the enemy?

What I mean is, when the spawner is BIG it takes up more of the screen than when it shrinks to the smallest point in the pulse.  But even in that state, the collision detection appears to be calculated based on the BIGGEST frame of the sprite - which feels cheap because you can be killed without actually touching the spawner in its smallest form without appearing to touch it.

Otherwise?  Looking really solid!

Alright, got a nice solid baseline of play, I feel ready to comment.

1. It is hella fun.  You have the spirit captured perfectly.  The flow of player and enemies feels well.

2. I'm using a controller and it works perfectly (dual analog).  However we MUST have input swapping for keyboard play.  I can't have move being the cursor keys and left-side keys be fire.  I had to play cross armed and I wasn't playing well because of it.

3. The enforcers have issues for sure.  I'm still putting my finger on why.  I THINK (without further analysis) that they need a delay with firing on player death respawn.  Once you have 4 of them on the screen?  And you die?  The game is pretty much over - as they will pin you with shots instantly upon spawn.  A lag in their fire (say a 3 second moratorium) just might fix that.  They are supposed to be genuine pain in the asses - and you have them working well otherwise, I think.

4. Nothing I've seen yet.  It is damn solid for early beta.

Other notes:

  • The game is harder without sounds.  We really need at least stand-in sounds because part of Robotron has always been about keeping track of enemies (like enforcers) by sound cues.
  • I swear there is something wrong with the collision detection on the stationary nodes.  It could be me trying to get to grips with the lower res, but "cutting it close" is part of the game's skillset - but I can't seem to "cut it close"; I end up dead.  I need to do further testing and watch  my own video playback to confirm the feelings on it.
  • Thought on Brains: in the arcade game there is one Mike and lots of mommies ... important strat on this level is to protect Mike as the brains are distracted and won't convert mommies so fast as long as he is alive.  Could we have an "odd" lemming that maybe works in a similar way?  Just seems like a big piece is missing from the level.

Oh, and I feel the "damage" on the hulks (the pixels displayed as you shoot them) are either too plentiful or don't disappear fast enough.  The clutter interferes with seeing enforcer shots ... That may be intended though -- I don't want to do direct comparisons with the arcade and not allow for artistic interpretation! :D