Ok, I just got 100% on this game, and I have a note to add to the guide since the guide thread is closed. On the "Heads I Win, Tails You Lose" achievement the method in the guide didn't work for me. What I ended up doing was going to a villain level, switched the second player to a goon and killed him ten times, and then went through the level and killed ten cops.
Games I'm currently taking invites for:
Soul Calibur IV, Soul Calibur V, Tekken 6, Super Street Fighter IV, MvC3, Puzzle Quest, Halo: Reach, Madden 10, Left 4 Dead 2, Borderlands, Gears of War 3,, Modern Warfare 3, Rock Band, MvC2, Battlefield 1943, Castle Crashers