harbingerdawn: Yes, SE does not directly require any features of Windows versions newer than 7, it's just that driver updates aren't available on Windows versions older than 10, so if there's a problem in SE that exists on older drivers but is fixed in newer drivers, you're SOL. This is why we list Win 10 as a requirement, but the program should run fine on Win 7 and newer.
Put straight: You deceive a customer on purpose by lying the game's minimum is not Windows 7. While saying here the minimum is 7. Is it OK? No.
Start to be honest, list 7 as the minimum, add a note that driver bugs for 7 won't be addressed, and that's all, everyone is in the know then. We all know 7 is EOL, nobody expects magic, and more people will be having fun. Is it hard to be honest with your customers on the store page? What are you doing? Do you get how it looks for us all? Many people use 7, you lose sales due to that, you know, and you lose trust as well. And for what? For a theoretical "future problem" that does not exist yet, like being scared of a monster under the bed.
SpaceEngine is an interesting project, more people deserve to enjoy it and know it'll run right away without digging the billions of pages on the forum. I think everyone can agree with that.