It's at least a D+.
Really though, the thing about people who assign arbitrary letter grades is, well, they're arbitrary.
Without providing some sort of point breakdown, it's just some dumbass letter that's been assigned with no real explanation. I prefer it when the review actually has some kind of point-thingy-breakdown.
The art comment made me LOL pretty hard. He's basically correct there.
They only got 18,000 points, though. So, clearly, they suck at the game. If you haven't gotten to the teal robots, you is a chump.