It wasn't a bad game, and it had a solid foundation, but the gimmick sort of wore thing pretty fast for me. It was like Sacrifice except not nearly as good, and the story fell apart about halfway through or so when it decided "Hey, we should make this all serious and epic" except that wasn't why any of us were playing the game... we were playing because it was funny. The gameplay isn't bad, there just wasn't really enough to do that had a lot of meaning, and the story started to take itself far more seriously than it ever should have.
Beyond that, the game is absolutely 100% worth buying just for driving around the world and seeing all the crazy metal-themed landscapes and stuff, though. That was the big draw for me, and it totally delivered on that front. Cheesy and goofy, but in the best kind of way. It was just a lot of fun exploring that stuff. It's a shame the whole package didn't come together better... I think they really just got carried away and focused entirely on the wrong elements. Play your strengths, Tim!