PICO-8 1k byte shmup rundown

1k_shmup.p8

pico-8 cartridge // http://www.pico-8.com
version 36
__lua__
--[[
	a - ammo
	h,v - ship coord
	t - frames (ticks) 0-30
	w - wave spawner, holds when the next wave will spawn
	d - difficulty counter
	l - lifes
	b - bullets {}
	e - enmeies {}
	p - p is not needed I think, leftover junk
	r -- rnd() remap for fewer chars
	k - del() remap for smae
	eb - enemy bullets {}
	ht - hearts {}
	ld - score holder in the end
]]
a,h,v,t,w,d,l,b,e,p,r,k,eb,ht,ld=20,64,100,0,0,0,10,{},{},{},rnd,del,{},{},0 -- shorter variable names
function ce(a,b,c,d,e) if (((a-b)*(a-b)) + (c-d)*(c-d) <= e*e) then return true else return false end end -- distance based collision
::_:: -- goto label
if time() < 3 then goto title else -- titles screen check
	cls()t+=1 -- frame counter
	if(t%2==1)add(b,{x=r(128),y=0,t=1,b=0,c=1+flr(r(2))*6}) -- every second add a type1 bullett, these are the starts in the bg with negative momentum
	if(t>30)then t,d=0,d+0.005 end -- reset frame counter to loop in 0-30, increase difficulty
	if(w<time())then --spawn new alien, i don't even use t, lol
		i={x=r(120),y=-2,t=r(3),s=r({1,2}),sp=time()+r()}add(e,i)
		o=2-d
		if(o<0.1)o=0.1 -- dafuq is this tbh
		w=time()+(2-d) 
	end
	if(btn(⬅️))h-=2 -- controls
	if(btn(➡️))h+=2
	if(btn(⬆️))v-=2
	if(btn(⬇️))v+=2
	if(0<(h+6) and h<20 and v>99 and v<113)a+=1 --ammo reload on proximity, could use ce collision
	if(btnp(❎)and(a>1))a=a-2add(b,{x=h,y=v,t=0,b=0,c=9}) -- shoot bullets, see type=0 those are hurting bullets going up, 1is stars in bg going down
	for a in all(b) do -- bullet movement update
		if a.b==0 then
			m=a.t*4 -- here we *4 the movement of starts (type 1 bullets)
			if(a.t==0)m=-2 -- flip movement to bullets, they should go up not down
			a.y+=m -- move all bullets (remember, stars are non colliding grey bullets)
			if((a.y>128)or(a.y<0)) k(b,a) -- remove them if they are under or over screen
		end
		tex=a.t==0 and "✽" or "." -- dot is star, shuriken is bullets
		?tex,a.x,a.y,a.c -- print them on screen
	end
	for q in all(e) do -- enemy update loop
		q.y,z,c=q.y+1,q.y,q.x -- save some stuff for cars
		if q.s==1 and q.sp < time() then ebu={x=q.x,y=q.y+4,s=r()*2+1}add(eb,ebu) q.sp=time()+r()*4 end -- shooting enemies, adding bullets
		te = q.s==1 and "☉" or "😐" -- enemy texture switch based on type
		?te,q.x,q.y,8 -- print enemy on screen
		if(z>128)k(e,q)l-=1 -- if enemy makes past screen, delete and lose a life
		for a in all(b) do
			p,o=a.x,a.y -- enemy and bullet collision
			if(a.t==0)and ce(p,q.x,o,q.y,3)then k(e,q)k(a,b)end
		end
	end
	for b in all(eb) do -- enemy bullet udate
		b.y+=b.s -- move down
		if b.y > 128 then k(eb,b) end -- delete if under
		if ce(h,b.x,v,b.y,3) then k(eb,b) l-=1 end -- player collision check
		?"●",b.x-2,b.y-2,r({8,2}) -- print with random color of dark or bright red
	end
	if time()%15 == 0 then hr={x=r(128),y=0} add(ht,hr) end -- hearth spawning in
	for hr in all(ht) do -- hearth update
		hr.y+=1
		if ce(h,hr.x,v,hr.y,4) then k(ht,hr) l+=1 end -- player collision to heal
		?"♥",hr.x-3,hr.y-3,rnd(15) -- print
	end
	?"/ホ\\",h-7,v-2,11 -- player ship print
	?"⬆️"..flr(a/2),110,0,9 -- ammo number print
	?"⬆️",2,100,9 -- ammo print
	?"♥"..l,0,0,11 -- health print
	if(t%5==1)?"◆",h-3,v+3,10  -- ship flame
	if(l<=0) then ld=time() end -- on game end save time
	-- Copies the graphics buffer to the screen, then synchronizes to the next frame at 30 frames per second. This basically is our 
  -- _draw() basically if you want to spare tokens not wrinting function _draw() end
  flip() -- draw call
	if l>0 then goto _ else goto over end -- if game is going, jump back to _ with goto and keep the loop alive, if not jump to over
end
::title:: -- title loop, which jumps back to _ to keep the game alive
cls()
?"1k defender",44,62,rnd({6,7}) 
flip() 
goto _ -- loop back up to keep game alive
::over:: -- over label which prints the score and stops the game
?ld,64,64,11 -- print time survived
__gfx__
00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00077000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00700700000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000