Mannequin Head is a jumping puzzle game. In Mannequin Head you are a disembodied head trapped at the bottom of a well. The only way you can get out is by carefully timing a series of jumps as you move towards the light. A series of sliding platforms will try to stop you but if you are smart enough, fast enough, and know-how to jump then you'll be able to use the platforms against themselves. Jump up and land on the platform, then wait for the next one to show up and time your jump to land on that one. As you climb higher and higher you collect stars which help guide and motivate you. Even if you can't actually escape the well you should try your hardest to get as far as you can, compare your numbers with other disembodied heads on the leader board and see which mannequin head is truly head and shoulders above the crowd.
Press the left mouse button to jump. Time your jumps to avoid the platforms but remember, you're supposed to land on them.