You play the game as Susumu or Anna. Equipped with nothing but a pressurized suit and a drill, you need to contact the King of the Undergrounders. To do this, you will need to drill down several thousands of feet avoiding being crushed and remembering to pick up air tanks.
This is a real-time puzzle game where you will be continually moving down or sideways in an effort to get to the bottom. As you dig, blocks will fall to fill in the spaces below. Like colored blocks will stick together (giving you time to rest), but will disappear if 4 or more blocks come together. This can cause chain reactions (very common in two-color levels) that become dangerous quickly.
Three modes of play: Story, Time Attack, and Endless Driller. Story Mode uses the bare bones story from above. Time Attack gives you a set levels with a specific time limit. Endless Driller allows you to dig for as long as you can.