Sorry for the shameless plug, but my games also use a ready-to-use JS game engine entirely developed by me. They don't look as polished as Biolab, but I surely enjoyed writing them.

A demo: http://ralphgoodtimes.com/webgame_chillyzombies.html

Source code here: http://ralphgoodtimes.com/webgames_info.html

Use it for both commercial and non-commercial purposes. I hope you enjoy it as much as I enjoyed developing them.