I am building a game using the Super Tux assets. It is NOT an asset flip, game has a totally different main concept, new mechanics, 4 new boss fights, built with a different engine.

When I first started building the game, it was supposed to be a FOSS game. But after spending a ton of sleepless nights working on it, I would like to get compensated.

Donations will probably not cut it, judging by what most FOSS games go through. I'm a huge fan of FOSS, so it does feel wrong releasing a commercial games where 80% of the assets are from volunteer work.

On the other hand, the license approves of this. If they have an issue with it, they would have chosen another license, correct?

What do you think?