A tiny shoot-em-up (shmup) game developed with just 492 characters of code for the 2025 TweetTweetJam 10. In this simple game, you try to avoid meteors by dodging and destroying them. You earn a point for each meteor destroyed, but the game ends if a meteor collides into you!

CONTROLS

• LEFT ARROW = Steer Left
• RIGHT ARROW = Steer Right
• Z (or O button) = Fire Lasers

For the 2025 TweetTweetJam 10, I had originally tinkered with a nonagram-style puzzle game. However, I was running out of time during this week-long game jam and ended up quickly exceeding the 500 character limit in the jam rules. Speaking of rules for the TTJ game jam, developers must create a game with just code - no external asset files, like spritesheets or sound files. To code your game, developers can use a variety of tools. Many choose the PICO-8 game engine because it allows coders to be creative with the Lua language and shorthand code permitted in the editor.

After half of the jam week had passed, I decided to shift gears and think more simply in terms of my game design and mechanics. I decided to try coding a basic shmup-style game that could be played with just 3 keys for shooting lasers and moving side-to-side. In the end, my tiny shmup game was entirely developed with just 492 characters of PICO-8 Lua code. I will likely continue development of my nonagram-style puzzle game, but it became clear to me that it wasn't the best fit for this fun game jam.

-- tiny shmup
-- by m4ttbit

x=64b={}e={}g=true s=0::_::cls()
if g then
 x+=btn(1)and 2 or 0
 x-=btn(0)and 2 or 0
 if(btnp(4))add(b,{x=x+1,y=120})
 if(rnd()<.02)add(e,{x=rnd(128),y=0})
 for i in all(b)do
  i.y-=4 rect(i.x,i.y,i.x+1,i.y+3,7)
  if(i.y<0)del(b,i)
 end
 for m in all(e)do
  m.y+=1 circ(m.x,m.y,3,8)
  for i in all(b)do
   if(abs(i.x-m.x)<4 and abs(i.y-m.y)<4)del(e,m)del(b,i)s+=1
  end
  if(abs(m.x-x)<4 and abs(m.y-120)<4)g=false
 end
 rect(x,120,x+3,123,12)
 ?s
else
 ?'game over',45,60,8
end
flip()goto _