Firstly, as I mentioned, this is no fallout 3. In fact, the game it reminds me of most is Diablo 2, but with guns and in 3D, and with a postapocalyptic feel to it. The other game that was similar was Hellsgate, but that was a dismal failure, so the less said about that...
Thing is, despite the very simple character development, the diablo-style weapons (even with colout-coded names for the better ones), the wandering around picking up side quests and so on, this game actually works. From the outset, the cartoon-style graphics of the intro (with all the different characteers sat on a beat up old bus, driving across some desert) you know this game doesn't take itself too seriously. The cartoon effect continues into the game, it's very odd and feels like walking around an old warner bros. cartoon, in clearly rendered 3d. Odd, but at least it's original, and I actually like the look.
There are also lots nice little touches. Like the little robot you meet (claptrap) that looks like it's randomly stabbing at the keypad to open the gate, then bumps it's head on the way through.
Finally, unlike many of the games that have been released recently, I installed this with no errors or issues, didn't download any patches, and have not seen a single bug yet (other than one instance of the AI not working well).
I haven't tried the (cooperative) multiplayer yet, but a friend who has assures me it is also well implemented, whether across LAN or using split-screen.
In fact, the only real criticism I had, was that the vehicle controls took a bit of getting used to. Instead of using the keys to steer, you use keys for accelerate/decelerate, and whatever way the camera is pointing, the vehicle will try to steer to point that way. A friend with the PS3 version said he found the dune-buggies odd to control there too, so it's not just that it's a console port.
So, if you are looking for some lighthearted fun, fed up of buggy games that crash and lock up, you just want to blow holes in alien dog-like critters and bandits while waiting for ME2, or just need a break from Dragon Rising, then you could do a lot worse than this. Even the intro made me laugh.