doing my final three achievements right now. i'm in round 5 of 20 on the Angellic Ruins for the Moxy's Underdome DLC...Hellburbia and completing the three longer challenges are all that i have left. you get the achievement even if you join in at round 19 and play through 20 so feel free to come lend a hand. any weapons and shields that drop go to you guys. gamertag Chief Trees, message me or just sign on and join the game. THANKS.