This is a puzzle/platformer where you must navigate through the two screens in order to get to the star at the end of each stage. The top screen is the blue world where gravity flows downward, and the bottom screen is the red world where gravity flows upward. When you travel between the two worlds, you conserve your momentum.

There are also spikes you must avoid, and doors which can only be opened by buttons. Place a block on the button to keep the door open.

Blocks come in three different colors – red, green, and blue. Green blocks will observe the gravity of the world they are in (like the player), but red and blue blocks will continue to act as though they are still in their own world (e.g., a blue block will fall down, even in the red world).

Currently all levels are unlocked from the beginning. The number of stars(*) next to each level indicates its relative difficulty.

http://www.neoflash.com/forum/index.php/topic,5563.0.html