That's great. <3 In first place I will make simple mechanics for the game and launch a demo. Later, the history mode goes to crowdfounding. The game can have a price?
This will be my first game, so it will takes me much time :P
There are absolutely NO limitations on how you use these models. You can charge whatever you want. You can modify them freely. You dont even have to credit me. If you feel like it, you can donate to me for them, but that's 100 percent voluntary.