- Not to be confused with key.
From versions 1.7 to 5.2.1, the player could get one World Key after beating the Gargantuar level in any world, but in the present version, after beating the Gargantuar level, the player receives a Key that is used to unlock the world after the one it was obtained in.
In the 5.1.1 update, the Gargantuar statue holding the World Key in every world except Ancient Egypt was removed to prepare for the "Keysplosion" of the 5.3.1 update which had the player receive a key chain containing 10 world keys, allowing all worlds to be accessed after completing Ancient Egypt - Day 8.
In the previous updates of the Chinese version, a World Key could be obtained by either beating the last level in the first three worlds, or by beating the level before the first boss level in the rest (Day 16 and Day 30 in Kongfu World, Day 29 in Far Future, Night 30 in Dark Ages, Day 30 in Big Wave Beach, Day 25 in Frostbite Caves, Day 24 in Sky City and Day 25 in Lost City). They were removed in the 1.8 update and the worlds are unlocked with stars again.
Additionally, a free World Key was given to all players since the 3.5.1 update to the 5.3.1 update as a reward for beating Ancient Egypt - Day 2. This key was won for all players by YouTuber ZackScottGames when he completed a Piñata Party challenge set by the PopCap team.
Before the 5.3 update, every player would still have spared two keys after beating all 11 worlds. However, from the 5.3 update to the 8.8 update, if the player had beaten Day 6 of Ancient Egypt, they always had their remaining amount of keys subtracted to zero.
World Keys were removed in the 8.9.1 update, with them being replaced by Keys.
- The player could only get more World Keys if the player decided to purchase a world instead of using a World Key, getting a free World Key, or unlocking Pirate Seas after beating Ancient Egypt - Day 12 for a limited time during April 2014, since the player didn't need to use the World Key.
- Each Gargantuar statue that was present in each area held a World Key.
- From Lost City and onward, all Gargantuar level statue designs were different, being a sculpture of the Gargantuar's fist holding the World Key.
- The advertisement for World Keys claimed that the player would find Gargantuars in Day 8 of each world. However, this was not true for Dark Ages and later worlds.
- In earlier versions, there was a glitch in which the player could randomly receive a large number of World Keys. This was fixed in a later update.
- When players updated to 7.9.1, they would get eight extra World Keys.
- There used to be a glitch where if you use the Ancient Egypt key on Modern Day, it will give you the keys for the other worlds, meaning you can unlock any world by beating Ancient Egypt after the first Gargantuar attack.
- The "Keysplosion" key chain consisted not only of keys, but also of: a pot charm, a Sunflower charm, a L.E.A.F. symbol key, a car key, a bottle of Hot sauce, and an antique key.
- The pot charm resembled the pot worn by Crazy Dave.