A super minimalistic mix of the classic Pong and Breakout games (without the bricks) in < 256 bytes of HTML and JS. Golfed by @aemkei, @subzey and ….
Use your keyboard to control the paddle movement.
<body onload=k=13,x=W=27,X=Y=1,setInterval('for(i=h="
",k=k<0?0:24<k?24:k,X=x%W?X:-X,Y=x<0?1:297<x?1%(x-299
-k)?p:-1:Y,x+=Y*(W+X*Y);i++<297+k;p.innerHTML=h+888)h
+=i%W?i^x?" ":0:"|\\n"',99) onkeydown=k+=event.which-
38><pre id=p>See the annotated source for details.
