Time Rings (Mechanic)

The Time Rings are a new mechanic inteoduced in Plants vs. Zombies 2: Unknown Eras DLC.

Overview
This mechanic gives extra challenges to unlock each world.

Time Rings are units that include a pack of Worlds and Epic Quests. World Keys are reintroduced with the function of unlocking other Time Rings, that are divided according to the time period. There is also a new type of World Key, known as Chrono Key. These new keys are obtained by winning a Time Ring-exclusive challenge known as Time Distortion and are needed to unlock Modern Day at the last Time Ring.

Division
These are the four Time Rings and their information: