I've created a couple of games with ImpactJS and have really enjoyed it. I think it's great for tile-based platformer games in particular. But (with enough prog

I've created a couple of games with ImpactJS and have really enjoyed it. I think it's great for tile-based platformer games in particular. But (with enough programming skill), you can bend it to make virtually any type of 2D game. The code is very well thought out and organized. It's a pleasure to work with generally. Haven't used any of the other HTML5 engines though.