I also am thinking about making my games open source and how that conflicts with acquiring money from them. The open-core business model may work but a lot of the other business models that work for other open source software do not work well for video games. Such as dual licensing. And if your making a core for others to make games with that works but you aren't really making a game at that point but a video game engine. Your games instructions were incredibly unclear. Apparently I had to double click on the card to make it work not click on it. And the right click to move was for moving the camera not the player. Even when I got the card to work I had to figure out that it required using it to its full extent to make it work. If it didn't I didn't know how to do otherwise.