Us vs Them

Energy falls with each shoot missing them.

Energy falls faster if hit by them.

Energy fills with time, as time's with us.

Left and right arrows to move, C to shoot.

Here's the complete program, ready to copy & paste to your favorite Pico-8 console:

f=foreach _=0r=rectfill
x=62y=110p={}v={}a=16
function _update60()cls(3)f(p,o)f(v,w)a=mid(-1,a+.01,32)r(0,116,128,128,0)r(-1,116,a*128/32,128,11)
?_,56,4,11
?'us',x,y
if(btn(0))x-=1
if(btn(1))x+=1
x=mid(0,x,121)
if(btnp(4)and a>=1)add(p,{x=x,y=y})a-=1
s=rnd(.5)q=.03
if(_/5%2>1)s=.1q=.1
if(rnd()<q)add(v,{x=rnd(114),y=-9,s=s})
if(a>0)_+=1/256
end
function o(o)o.y-=2
?"^",o.x,o.y
if(o.y<0)del(p,o)
end
function w(w)w.y+=w.s
?"them",w.x,w.y,0
if(w.y>110)del(v,w)a-=2
for o in all(p) do
if(o.x>w.x and o.x<w.x+15 and abs(o.y-w.y)<2)del(v,w)del(p,o)a+=1
end
end