http://www.stonetrip.com/
http://www.devmaster.net/engines/engine_details.php?id=499
According to the devmaster page and the site, it has 2D filters, Physics, AI, editors, it has pretty much everything you could want, and they have a PLE edition too.
Now I’m one who’s sticking with an engine I already have (the BGE), even though I have around enough money to buy the $1,800 price tag for the pro license.