Object: Automatically fill any user-defined playing area with the given Y-pentomino. Watch the operation of a backtracking program in action and enjoy the solutions it comes up with! 
 
To start, click the grey playing area. Zillions will AUTOMATICALLY tile the area without gaps or overlaps using copies of the polysquare shown in the top left corner.
 
Given a shape and a tile to fill it with, it is in general not known whether such a tiling problem has a solution. This game gives you the answers (if Zillions does not run out of memory) and lets you watch as the computer plays with the tiles.
 
YOU CAN GIVE THE COMPUTER ANY SHAPE MADE FROM SQUARES. (You can REDESIGN the fill-area very quickly and easily, either by deleting or adding new positions via selecting 'empty' or 'T0' with your right mouse button or by changing the board setup in the rules file.)
 
THE PROGRAM WILL DO EVERYTHING ELSE FULLY AUTOMATICALLY!
 
The system will stop (win) when it has found a tiling, and also stop (lose) if there is no tiling for the given shape.
 
This game presents a collection of
- all 23 Y-primes which fit onto a 32x32 board
- all 7 Y-primes which fit onto a 50x50 board
 
There exist only ten more primes for the Y-pentomino: 9x55, 12x55, 12x60, 12x65, 12x70, 12x75, 12x80, 12x85, 12x90, 12x95.
 
Please note that there are six alternative piece sets available.
 
 
See also Zillions games Ypento, Y-primes, G-Primes and Reptiles, Reptiles II and Backtrack for similar puzzles.
 
More freeware as well as real puzzles and games at my homepage http://karl.kiwi.gen.nz.