Just finished Rage last night. Overall it was pretty fun. It got a bit repetitive towards the end, however this is to be expected out of a game that runs 20 hours. That's right, I got 20 hours out of the single player! I can't remember the last time I got that much play time out of a game. I did take my time, and explored everything. Likely could have cut it down by 5 hours if I'd have rushed. I didn't complete all the racing events either. It was a pretty decent shooter. The difficulty ramped up nicely, to keep it challenging.
It had minimal RPG features, which is fine with me as that's not my cup of tea.
The only downside is that it just kind of ended. The story had a very short wrap up, after spending that much time playing.
Still worth the $30 I paid.