I can see the reasoning behind trying to make a better game to garner the longer playing times- but after a certain point, if development of the game has some publicity, the attention on it gives you a sense of how well received it might be when released. At that point, why not just sell it for a fair price?
I would rather sell a good game at a fixed price, and then maybe once sales have decreased, make it available on this sort of platform at a later date.
This sort of strategy makes more sense to me- Develop the game with intentions on selling it at a fair price, and then think about this sort of thing after the game has sold.
I don't think this system will affect the quality of content available, because if it is easy to add your game, anyone will do it even if the game isn't great.