I've been playing
alot of
Minecraft lately. It's creator has described the game as a mix between
Roller Coaster Tycoon and
Dwarf Fortress. Dwarf Fortress having an immense learning curve but an super impressive dungeon crawler, and the iso-metric ease of approach of a Roller Coaster Tycoon type game. The game is still in Alpha development, but has already sold an amazing 600,000 copies. With my love of
rogue-like games, this is a fun dungeon crawler, and it has cool physics and mechanics. And it's still in Alpha development, so it should eventually be a barn-storming smash (if it isn't already).