Can't stop playing this game

[Belmit]

Even though I've done all the levels! It starts out fairly easy but soon gets pretty tricky, and the white levels are hard to see on some monitors. You just have to draw shapes to get the ball (or square) to the flags. You basically start out by plugging the holes and just nudging the ball around, but later you have to start building contraptions like trebuchets to get the ball around. Bloody addictive, and infuriating.

http://www.miniclip.com/games/magic-pen/en/