Don't buy it, just don't.
The game itself is nice, fancy stalite images and stuff. The reason why you should not buy this is the following:
This game uses not steams licensing model. You need to enter a Serial-Code to unlock it. You get one of them when you buy the game through steam. But as soon do a clean reinstal (for example new OS setup), you have to enter the key again and you get a message saying "The key is already in use". I contacted their support three times (with 2-3 weeks between every email) to ask them to reactivate my key. They just ignore you and dont answer. Even when I thread them in the 3rd mail to take legal steps they just ignore you and don't answer.
After that I contacted Steam support and asked for a refund, as I obviously paid for a product I can't use now. They just told me I have to contact the Ikarus (author company of aeroflyFS)...
To this day I still have this game in my library that I waste 50$ on and cant use it because of their bad customer support.
Please do not buy this and do not support such a company! They just want your money and leave you with an unuseable product after!