The ZX Spectrum game originally created by Malcolm Tyrrell brought to Android.

There are 29 hand-crafted levels. The puzzles have been shown to be NP-hard.

Navigate the mazes in as few moves as possible. Submit your number of moves to the online scoreboard to compare scores with players around the world.

Move the player by swiping up, down, left or right. Obstacles may be pushed left or right. Pushing an obstacle will move all obstacles of the same type. Obstacles may not be pushed through walls. The player may not move through walls. The puzzle is solved when the player has reached the exit door. Simple.

Source code is available via in link within the app.