Day 2 Patch: Leaderboard support and various fixes.

Leaderboards!

Now, after beating a level, you can compare your completion time with the rest of the world! Pressing Y on the controller or C on the keyboard on a level's door will bring up a leaderboard tailored to your current difficulty.

Bug fixes:

• Replaced Xbox controller plugin. Should work for everyone now.

• Achievements now pop up immediately, not on closing the game.

• Many insignificant things.