OCO is a sliding and jumping game set with simple colourful levels each set in a rotating planetoid. Unlike other platform games, you control everything with a single button. Each different colour of platform you slide along grants different abilities and you change direction when you hit a wall. You need to not only time your jumps but plan your route.

Play involves working through the 180 hand-crafted levels to collect each of the small orange boxes. Although you only use one button, you can still launch, rush, crash, glide, warp, and hang. These abilities are all triggered by a single button and determined by the colour of the platform you last touched.

You are awarded points for completing levels in the quickest time and with the fewest taps. At the end of each level, you get a score that you can perfect by repeated attempts.

The game includes a level designer so you can create and share your own designs. You can also try out level designs that other people have created and share in the community. There is an avid and active player base competing to create the best levels and get the best times on other people's levels.

The result is a precise platform game played with one button. The simple visuals are complemented by audio that is procedurally generated by your actions in the game. It might seem simple but actually offers a nuanced and complex challenge.