To unlock Zombie Survival Mode in this summer's hottest side scroller beat-em-up, hit down, up, right, down, up right, down, up, right, right, right from the start menu.

You'll be prompted to choose a character and difficulty, though the difficulty is largely dependent on how you've built up your character's stats and their level. I wouldn't recommend going into it without working on your stats first.

You'll be placed in an online leaderboard based on your KOs and survival time. I had 74 KOs in approximately 5 minutes on my first try on Easy with a level 16 Scott. At the time of this post, the top ranking had over 850 KOs within about a half an hour. There's a lot of fun to be had here, even if you've already completed the game.