This is just plain awesome. Created for the Experimental Gameplay Project, the theme was 'Unexperimental Shooter'. I'm not 100% exactly what that is meant to entail, but Petri (of Crayon Physics fame, of course) has made something fantastic.

Post I.T. Shooter has a stop-motion thing going on involving post-it notes and it works so well. Players move their ship using the arrow keys and press space to fire at the randomly-generated alien invaders. There's not much to it gameplay-wise, but who cares when it's that incredibly amazing to look at!

Download it from Petri's blog.