Dungeon Keeper 2

A sinister force has been summoned to topple the surface kingdom of Harmonia, whose ruler King Reginald has long maintained peace through twenty enchanted Portal Gems distributed among noble guardians, each one sealing away the darkness trapped beneath the world. The player takes on the role of an evil dungeon keeper conscripted by a powerful entity to retrieve these gems and breach the barrier separating the underworld from the realm above. To succeed, the keeper must carve out vast underground fortresses, recruit grotesque creatures to serve as minions, construct deadly snares and barriers, and methodically work through each guarded domain to overwhelm its champions and claim their gems.