I'm sure you're already aware of some issues given it's an in-development build, but the boss dragon shown in your gameplay video never spawns and leaves me unable to fly no matter how many times I reset or redownload. That and the pause menu doesn't seem responsive to my inputs.
Otherwise, free flying is very fun! A bit of a learning curve to get used to the physics but I like it a lot! I'm really enjoying the vibe you're going for. I think you have a really solid concept on your hands. Looking forward to the next demo, it looks like things have already progressed a lot by the instagram updates :)