The game looks interesting. Have you thought about business models? These days F2P often works the best if the game has enough play hours (1000+). If the play time is shorter, then some kind of trial mission is a good idea, so people can play it and whet their appetite. Yet another alternative is just having such a low-price people will pay just to explore, like the original $15 price of minecraft.
When is the release going to be?