Amazing graphics and very fun gameplay!
The graphics are absolutely A-M-A-Z-I-N-G!!!
The plot and environment felt to me like a Borderlands/Metro 2033 hybrid so after playing these 3 titles, I think I'll take a breather from post-apocalyptic games for a while.
There's a lot to do in the game and still it's not very long. It's not short either. I'd say it's just about the right length IF you do all the side missions and find the Easter eggs and IF you plan on playing some of its multiplayer mode.
The driving and racing parts of the game are a nice touch too.
I would suggest one important thing: If you're not a newbie and you like the game to be somewhat challenging, I would pick a difficulty that's above 'Normal'.
Spoiler ahead:
It's too bad you get the final weapon of the game just before starting the last mission. I didn't get to use a single BFG round :(
Also, your final battle consists of a swarm of weak enemies (and no boss) and it's not much of a way to end such a good game.