Eversion is a short platform game for Microsoft Windows by Zaratustra Productions. It features a small flower-like protagonist named Zee Tee, who is on a quest to rescue a princess, collecting gems along the way, much in the style of early Mario games. Each level consists of a set of parallel realities, each of which features different hazards, a unique artistic style, and a distinctive soundtrack. By using Zee Tee's ability to "evert" from one reality to another, the player can navigate him through obstacles to reach his goal.
The opening screen and the first few levels are quite cheerful and colorful. The game was inspired by a quotation from H. P. Lovecraft and it features a warning on the intro screen that it is "not intended for children or those of a nervous disposition".
Eversion is free to download, but a high-definition version can also be purchased on Steam. Later versions of the free game feature an updated soundtrack and a completely overhauled final level, while the high-definition version features additional options and more detailed artwork.
The player controls Zee Tee by using the arrow keys to move left and right, the Z key to jump, and the X key to evert. Enemies can be dispatched by jumping on their heads; if Z is held down while attacking an enemy, Zee Tee will bounce high off its head, allowing him to reach higher platforms. Blocks with faces on them can be struck from underneath to yield gems.
Eversion is possible only at certain points within each level. Upon approaching an eversion point, the music of the possible destination becomes audible. Additionally, the screen becomes slightly darker or lighter. Everting at this location switches between two adjacent realities. Switching to a third requires visiting a different location from the proper starting reality. In total there are eight possible realities, though not every level makes use of all of them.
Eversion allows the player to exploit the properties of the different realities. For example, in the first reality, clouds are visible as scenery, but they are intangible. In the second and third realities, clouds are solid, allowing the player to reach previously inaccessible areas. Plant-based objects also change, becoming solid, passable, or deadly depending on which reality is being visited, and certain bricks change from being solid, to breakable from underneath, to disappearing if Zee Tee steps upon them. Enemies move at different speeds and show very different attitudes from one reality to the next.
Collecting the gems strewn about each level confers no benefit during gameplay, but collecting all of them—over the course of several attempts, if need be—allows the player to access a secret level and, at its conclusion, see a different ending to the game.