Mine down to collect various ores and sell them to upgrade your machine speed, fuel tank or storage capacity. Find treasures an earn achievements. However, pay attention that you don't have unlimited fuel so you might want to get back to surface sometimes to recharge it. Also you can build awesome stuff to visually upgrade your house and increase it's level. For each level raised you unlock new upgrades for the drill.
- Achievements and treasures - Custom size of the world - 4 different machine upgrades - 2 game modes (Normal / Dark) - 5 types of ores and rocks - Level based unlocking system