Welcome to the very belated addition of online multiplayer. Yay! This DLC is incredibly easy but you will need at least 1 other person to play through it with online. If you can't bug a friend into helping you then take a look at the Boosting Session Calendar to see if there's a session for the game or try setting one up.
Once you have a partner to play with, set up a game and select Wallace as your character of choice. You'll now need to play through and complete the game once again. The good news is that you don't need to complete the full levels and just like we did previously, you can just play through the boss fight stages.
Once you complete your first level you'll unlock the following achievement:
Continue through and once you complete all of the levels with Wallace you'll unlock this achievement:
For the next achievement you need to play online as each of the characters (Nega-Scott and Chau excluded). So to do this enter a level, hit start and then quit the game. Set up a new game and then select one of the following characters: Scott, Romana, Kim or Stills. No need to worry about Wallace, we just completed the game with him. I'd suggest you play through all of level 3 each time as you need to work on racking up 200 kills for a later achievement.
Each time you complete the level, repeat the process of quitting out, setting up a new game and selecting the next character until you unlock this achievement:
Once you've unlocked that, there's only 1 more achievement left (which you may have even unlocked already). It's simple enough and requires you to have KO'd 200 enemies in the online mode. If you haven't unlocked this yet then continue to play through the third level and remember that the crowd that storms through at the start all count as enemies.
This accumulates across every character, so with your playthrough earlier with Wallace, plus your run through this level with each of the characters if you haven't unlocked it yet; you shouldn't be very far off it at all.
And there you have it, all done. Congratulations!
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