In Overhaul you have to protect your mining station (Big elongated spaceship) by placing and combining the modules which will fall from the sky. If you can match three modules, a higher level module will be created to take its place. You can click on a module to reveal information about it.
As well as modules, you're also equipped with missile launchers, freeze bombs and a module repair facility (For repairing damaged and nearly destroyed modules).
As you progress through the game, you will discover new abilities, modules and weaponry. You will also be given the opportunity to enhance your pre-existing utilities.