A guilty pleasure - I'm enjoying it more than I probably should.
After getting into it a bit more (15+ hrs), unlocking characters, figuring out how to drive, etc., and when I stopped comparing it to what I wanted it to be, I started to really enjoy myself. A lot. No, it's not ground breaking, and it won't blow you away. But, it is a simple and fun, Contra-style shoot 'em up, especially if you like couch co-op.
I like the variety of playable Joes and Cobras (an unexpected bonus as I always prefered Cobra for some reason). The difficulty settings are about right - a tad too easy on casual, a little too hard on hardcore. Add to that some variety of settings, data files and such to collect, and being able to replay any mission gives the game some good replay value. The criticisms of the game that I've seen aren't inaccurate, but they don't tell the whole story either.
Overall, this game may not match up to everyone's tastes and expectations, but I feel like I'm getting my money's worth in entertainment.