Licence.txt

The Polyomino Free Software Licence

This is open source software and it is free, in both senses. You are free to 
download it, use it or modify it and to create games with it. You may also 
distribute this software or your games created with it or use it to offer services 
to others provided that:

1. You do so on the same terms as you received it, by including a copy of this licence
2. You retain in the source code or other materials all copyright and attribution notices
3. Any such distribution or services are also free of charge.

Open source is recommended, but not required as long as the game is free and 
distribution or services are on non-commercial terms.

Since games depend on content the rules apply not just to the program code 
and the game scripts but also to every image, icon, font or sound 
clip that is part of the game. Free means free.