Zombie map is good. It is set in germany where the zombie 'outbreak' started. You spawn next to a machine which just closes (due to the power being out), this machine upgrades your weapons (cost 5000 points). So you have to start up the power in order to get the machine going. To do this you have to go to the power source and switch it on (past a few doors and next to the gun box). Once this is done you have to get all 4 teleporters linked up (cost 1500 points to use however first go is free) and this is done by holding onto X while quickly running back to the exit tele (next to the machine where you spawn). For each tele you link the 'perk-a-punch' door goes down. I only upgraded my pistol for fun and turns out you get grenade bullets for the gun (40 bullets). You can also buy a new knife for 3000 points which is a one hit kill on zombies untill round 12-13 (ive heard). Another new weapon is the monkey bomb, this weapon gets the zombies attention by dancing around and once the timer runs out the monkey blows up and killing anything around him (apart from your team mates). New skins have also been added to the zombies revealing the skulls and the zombies doing some form of a nazi walk when coming after you.
Sadly some people have already found glitchs and therefore reached round 1000+ already in the leaderboards.