Well, OK, technically you're an "Earth-like planet" called Terra - a name which, since the dawn of time, has translated to "Earth, but we don't want to call it that for some reason." Totally-Not-Earth's sun has decided to pack its proverbial bags (read: fire, because that is the only thing the sun owns) and relocate to another galaxy, so our largely inhabitable landmass goes along for the ride. And thus begins a wacky road comedy with appearances by the likes of Zack Galifinakis and Mercury.
OK, actually no, Necro Gaia's an impressively challenging arcade-y experience where the only thing you can directly control is the speed of your orbit. All the while, meteors, stars, and the like attempt to pummel your puny planet, but you can stave them off by briefly summoning other planets - one of which has a lighting shield, another fireballs, another ice blasts, etc. And then you eventually fight a giant space snake. It's tough but fun, and you can download it for free here. Thanks, Indie Game Magazine.