Keys are collectible items that are used to get through locks.
To collect a key, come into contact with it. It will then appear at the top left of the screen, and the key will disappear. Hitting a lock while having one of the same color will cause the lock to open and the key will disappear. If the player does not have a matching key, it will not open.
There is currently a glitch where if the player has the key and falls on top of the lock, the lock will usually open immediately but the wheel will not fall until the lock completely fades. Rarely, this won't happen.