Taken directly from their site:
Dungeon Empires is a next-gen free-to-play 3D browser game that presents a unique mix of tactical role-playing game and dungeon editor. Prove your skill as a dungeon builder and create your own lair full of monsters and other dangers. Those who dare to enter your dungeon must not be allowed to make it out alive! Explore and plunder other players’ dungeons, fight against terrifying creatures and loot new monsters, rooms and items to make your chamber of horrors even more deadly and grandiose.
The game can be found here:
http://dungeonempires.gamigo.com/
What do you think about this game? Personally I find it quite good.