Approximate time for all: 3-5+ Hours

Introduction:

In Onslaught, two players go head-to-head in an attempt to clear waves of oncoming enemies. Chaining combos provides the key to success in Onslaught as this will send enemies over to the opponent's screen, the more that are sent over, the quicker the victory will be.

Step One: Take The Stage

It is suggested that you knock this one out first. Load up three different stages/maps and achieve victory over your partner/opponent.

Step Two: Killer Combo

Truth is, you will probably obtain this achievement without trying. All you must do is string together a combo of 30 enemies and the achievement will be yours.

Step Three: Kill or Be Killed

This achievement can prove to be frustrating but if you have the Catacombs Stage (Gamestop Pre-order Exclusive or you can purchase it for $1 [80MSP]) it will be much easier than expected.

Step Four: Surrounded On All Side + You Are S.O.L.

This achievement will come naturally over the course of playing through Onslaught Mode and working on the other achievements. For 'Surrounded On All Sides,' you can check how many enemies you have sent over by opening the Records in the Main Menu and going to 'Extra Content -> Onslaught.'

Send 2,000 enemies to your opponent's map.


This achievement will come naturally through your playing of Onslaught Mode. There is no way to boost this, besides playing with a friend. It is suggested that you play your best and try to get to the end of every match by letting the timer run down. You can check how many enemies you have sent over by opening the Records in the Main Menu and going to 'Extra Content -> Onslaught.'

Defeat your opponent and achieve victory in 3 stages.


Just as the descriptions states: achieve victory on three different stages/maps. The three stages that are included with the game are Urban Chaos, Steel Beast, and Mining The Depths.

Achieve a 30-combo chain.


This is one of the easiest achievements for Onslaught mode. Simply kill 30 Zombies/J'avo in a row before your combo meter breaks. Once you have reached a combo of 30, all the enemies will be sent to your opponent's map and the achievement will unlock.

Defeat your opponent 10 times with enemies you sent.


There is no preferred map for this achievement, although Urban Chaos seems to be the most common choice among players due to the presence of Bloodshots and Zombie Dogs (which can kill you very fast). Make sure to communicate with your partner at all times.

Player 1 (who isn't going for the achievement) should let themselves lose some Health during the beginning of the match.

Player 2 (who is going for the achievement) should build up a combo of at least 15 enemies before sending them over to their opponents map.

"Sent-Over-Enemies" will have a green outline/color so it is easy to tell which enemies belong to your opponent. Player 2 should let Player 1's Zombies down them, and hopefully those same Zombies finish Player 1 off.

Win while in the dying state.


It is suggested that you use the 'Catacombs' Stage for this achievement. The method is quite easy actually. There are spike traps located around the stage. Have both you and your partner stand in front of the traps and make sure you have a clear line of communications with them.

The player who is not going for the achievement (Player 1) must purposely walk into the trap, which will down them in the process immediately.

The player who is going for the achievement (Player 2) should about 5 seconds and then walk into the spike trap as well.

Player 1 should, at this point, be getting attacked by zombies and losing health as their "Stand-Up" meter reaches 100%. If done properly, Player 1 should die while Player 2 is still in the downed state.