How many characters of code did you use?
560

If you're comfortable with it, paste your game code here, so we can marvel at your achievement!
// script:js
var h=136,p=h/2,w=240,d=1,s=20,u=p-s/2,t=0,e=false
var c=[]
function ran(min,max){ return Math.floor(Math.random()*(max-min)+min)}
for(i=0;i<20;i++)c.push(u)
for(i=20;i<w;i++)g()
function g(){u=Math.min(h-s,Math.max(0,u+ran(-3,4)));c.push(u)}
function v(){for(x=0;x<w;x++){for(y=0;y<h;y++){if (y>c[x]&&y<c[x]+s){pix(x,y,3);}}}}
function sh(){c.shift();g()}
function TIC(){cls();if(!e){if(btn(0))p--
if(btn(1))p++
v()
sh()
pix(5,p,6)
e=c[5]+s<=p||c[5]>p
t+=0.1
print("s:"+Math.floor(t))}else{print("s:"+Math.floor(t),w/2-20,68);if(btn(4))reset()}}