Depends on who you ask. Many did not like the RTS elements, but liked that the game is a tribute to metal and that much of themes are inspired by Metal in general.
Also Jack Black is the main character.
If you do get to play it, just set difficulty to Easy and enjoy the ride.
Good music, at least. Driving around in the car, rocking out to Electric Eye and When the Night Falls ... And then an RTS comes out of left field and donkey punches you.
How much of the game do the RTS elements take up? I've heard some pretty bad things about that.