It used to be a good game. But, once you level up, everything changes. The higher you get, the worse the player base becomes. Even sticking entirely to the co-op against the AI (which is way too restrictive, they need to code some different bots), you'll find that past the first five levels, people are jerks. To be polite.

If I wanted to continuously wipe my account so I could stay a newbie, the game might be interesting. But I don't, and I have no desire to hang around the higher level playerbase, who remind me of every bad internet stereotype I've ever heard of.