Are you ready to help in solving one major problem? Well, if you do, that means you have to deliver the enormous amount of minerals to the primary building. Dig them from the ground and upgrade your ship.
Explore the underworld inside of a driller and find as many minerals as you can. Upgrade your tiny driller and get a better engine, drill or other parts of the machine, that may help you in exploring the cave. However, some unexpected troubles may hide deep in the ground. Dodge underground creatures, black holes and water pool, otherwise you will get damaged.