Here is the list of secret features that have been found so far. We can just keep them here so we a single place to find them.
Beta 1:
Minigame menu - To unlock: on the game type select screen, press up, up, down, down, left, right, left, right, random, random, random (not any random button, but THE random button) and a special minigame game type will appear
Beta 2:
Dizzy Mode - To unlock: 5 kills in a row without dying by different two players, and 3 ice block kills
Moonwalk Mode - To unlock:

Wind Mode - To unlock:


- To unlock:
