Keycard

Keycard is a special item found on the final level in both gold containers and dropped off of monsters. They can open up doors to rooms in the center of the ship before the boss.

There are 4 rooms in total, meaning the player will need 4 keycards if they intend on opening all the doors (this can be done with only two keycards with the proper items; see the "Secrets" section of the final level).

Collecting four keycards in one game will also unlock the Wicked Ring (they don't need to be held all at once, using one before picking up the fourth is acceptable).

The player who picked up the keycard is the only one who can unlock the door; make sure to pay attention to who picks them up, as sometimes they won't notice. At least one room will always contain one golden container.

Keycard