Generally, a barren wasteland. There are pockets of radioactive waste here and there, so you're going to want to bring a G-box with you, since that'll tell you before you're already dead. There are a few places that aren't complete fucking hellholes: these are the Preserves, places where the terraforming actually took hold. You don't want to go there, because they're all ruled by ruthless, sadistic bastards who'll do things to you that there aren't names for, just for trespassing. Otherwise, get used to plenty of squalor, 'cause that's the nicest you'll find.
There are two suns — Afterburn and Feckinbrite — which means it's daytime for about 20 hours at a stretch for three-quarters of the year; you can catch 6 or so hours of dark when you're lucky. For the Dark Season, Feckinbrite eclipses Afterburn, and the nights get longer as the days get cooler.
You’ve also got Prefabs: cities plunked down by the latter stages of the terraforming process, ready for human occupancy if you could only just figure out where the hell they are. Find one, and you’ve got the ultimate hardhold. Find one, and expect to be fighting off the rest of the dogs until the end of your days.
Bottom line, you’re looking at something about the size of Earth, that has been fucked beyond belief by terraforming that went bad. How long until this rock shakes off your kind like a spasming hemorrhagic fever patient? Are there colony ships up there, still in some kind of working order, that could take you to another, more hospitable place? Or are you gonna die here like everybody else… and then rise up again with an appetite for living flesh?
Probably that last one.