Mouse only. 

Explore the surface of the planet, collect matter (darker tiles tiles are worth more, and larger grouping multiply the score!) to make upgrades to your ship. Repair the communication device to investigate a mysterious signal...

Depth 100 contains heavy metal necessary for upgrades. 

Depth 200 contains gas. 

You will need to upgrade metal capacity in order to unlock Depth 300 and beyond. 

Every new depth reveals more story through the comms. device.