IMHO, Phaser is the best HTML5 game engine for intermediate + advanced coders.
I made Mod Studio (www.modd.io) to help beginners to develop "multiplayer" HTML5 games.
- No programming skill required
- No downloads (modd.io has an in-browser game editor)
- 100% Free
It takes 5 minutes to make cell-eater type games: http://modd.io/play/cell-eater
Here are a few games that were made using modd.io
I'd love to hear your thoughts + feedback!