At fist I thought about release a sokoban game on the app store and sell level packages (I'm trying to make some buck out of it) but the someone told me about the insatisfaction a game with no end can bring to the player, I was thinking about selling the game as a never ending sokoban game, meaning that you would always have a level to play.

You can check out some of the generated levels here:

https://victorribeiro.com/sokoban

Press "R" to restart the level (if you're on a computer) - CLick the Screen to restart the level (if you're on mobile)

I have a more sophisticated version where I give the player stars after the end of each level based on how many moves they made. (if I can generate levels I can solve them and tell you the minimum amount of moves necessary to do it.

Anyways, that's it. I think it's a cool project and could help me make some money, but I don't know a good way to make money out of it. Any suggestion is appreciated.