Ruin

Ruin is an isometric, dungeon-exploring game, in which you delve through a never-ending series of randomly generated floors, while dealing with the denizens of the dungeon, all for treasure. Basically, it's a roguelike with isometric graphics.

Waiting on floor 100 of the dungeon is the Liche, who has stolen an artefact of great significance - the Golden Sword. If you can retrieve it and escape the dungeon, you win.