Ikaruga is a shoot-em-up spaceship game along the lines of R-Type and Gradius. It's got a simple gimmick. If your ship is black, you absorb black shots. If you're white, you absorb white. Shots of the opposite color destroy you.
This is a video of a guy playing through one of the levels of this game, controlling both players in a two-player game. He dies once, at the boss, when he messes up and runs into a wall. Other than that, it's flawless.
http://video.google.com/videopreviewbig?q=...t+3%3A06+AM+PDTThis is the most insane thing I've ever seen. I don't think I could do that controlling one ship. In fact, I know I can't. This game eats me for breakfast. It's freaking HARD.