Terra Cresta takes place on an unguarded planet that is being invaded, where you must make successive passes over the landscape, shooting out ground turrets and aliens. Numbered bases release power-ups when shot - these can either be used in combination or, by pressing the space bar, in Formation Mode, covering a wider range of shooting positions.
Each pass over the planet ends with a boss battle; the third and final one is particularly challenging, as it can only be defeated if you are at maximum power. If you lose, you will be sent back to the start of the world.