A while ago I wrote a generalized version of Dr. Mario in c++. It wasn't pretty, and wasn't set up as a game. It was set up as a basis on which to mess around with making a computer player. The base got to a decent point, and then I realized it was hard to write a smart program to play the game, so the project stalled. Then I thought it might be fun to make it more web-based. I'm not sure 'fun' is the right word, but it might be worth a go sometime.