Realm of the Mad God is the latest Free to Play game on Steam. The description says it’s a “MMO bullet hell shooter. Fight monsters in groups of up to 85 players!”

Sounds pretty cool. Browsed around quickly through the Steam forums for RotMG and there seems to be some good feedback on the game. One guy said it’s the best F2P game on Steam besides TF2. He compares it to Dark Souls (which I’m hoping comes out for PC).