In Temporal, players control an unnamed robotical being which cannot recall his past and tries to figure out where he is, and his purpose. With only a propeller on his head, players control the quirky robot using only the arrow keys - interacting with the environment in order to advance and learn more about their surroundings.
The game focuses on puzzle solving and the unraveling of a continuous story that require the player to use the environment in various ways, such as pushing boxes around, destroying floors, manipulating chemicals, using automated guns and activating terminals and trigger beams.
However, the core of the game requires the player to time travel back in time, and interact with his past selves in order to solve a puzzle. Doing so might cause a temporal paradox that may create an impossible situation - however the game allows these transgressions and only gives a score penalty for such acts - often resulting in a butterfly effect.
Source: Wikipedia, "Temporal (video game)", available under the CC-BY-SA License.