 Tarn took some time off Armok to work on small side-projects, and another one which would inspire Dwarf Fortress was Mutant Miner. It was turn-based loosely inspired by a game called Miner VGA. Mutant Miner involved the player digging underneath buildings, searching for ores and fighting monsters, and carrying radioactive "goo" back to the surface for application in growing extra limbs and gaining other abilities. Adams was dissatisfied with only having a single miner, and the game began to lag because it was turn-based. Adams said:
