In Valley players play as an archaeologist who comes across a piece of abandoned World War 2 technology known as the L.E.A.F suit. The L.E.A.F suit gives the player superhuman abilities, most notably the ability to sprint at super speeds and jump extra high. The suit also allows the player to resurrect as well as kill any lifeforms it sees. Players must use all of these abilities to successfully complete the game.
For lives the game uses a unique mechanic whereby the L.E.A.F suit will resurrect the player if they die, but will do so by sucking up the life energy of the surrounding area, meaning the player has to keep the environment alive in order for them to stay alive themselves.