Trousers (a guy on my friends list) and I had a go at cracking the get-30,000-points-in-co-op achievement today. It took a few attempts, mainly due to the horrific lag which kept causing problems, but we finally did it with a score of 31,000-ish.
Or at least, that’s what we thought. It seems that although we broke the score needed, neither of us actually gained the achievement. Surely we don’t need 30,000 each? That’s plainly impossible in single player anyway, but in super-lag co-op? No way.