Mos Speedrun features 25 levels, across 5 worlds. Levels 2-5 are unlocked by earning badges through completing tasks on earlier levels.
- Complete the level.
- Complete the level under the speedrun time.
- Find a crystal skull hidden in each level.
- Collect every coin in the level.
The game has a replay ghost feature that is enabled by default, which means every past attempt is shown as semi-transparent characters as you play a level. The fastest replay ghost is rendered differently so it can be used to judge your progress when attempting to speedrun a level.
There is no combat in the game, all enemies and hazards are deadly. The game features some dynamic objects like moving platforms and falling blocks.