On Cmnd (short for On Command) is a time attack arcade game based around the concept of following a list of seemingly simple rules such as "Press Red" or "Avoid Red" to determine which button on screen to tap or click. More and more rules will appear at once, making things more and more complicated and confusing as the game progresses!

Note that you only need to press one button to progress. If a series of commands is shown, follow them in order and then press a button that matches the commands given. Correct answers will flash after a button is pressed or you run out of time.

There are a total of 16 regular levels and 16 additional challenge levels that are unlocked as you defeat each level. You can also create your own custom levels and place them on your computer (in the "levels" folder next to your savegame, in "%AppData%/on-command" or "~/.local/share/on-command") for extra fun.

Colorblindness accessibility is available in the options menu - there you can configure the four basic colors the game uses to be easier to see.