Hey, thanks for taking the time to play the demo, and for providing your feedback. Let me try to answer some of your points.
Regarding the grass, yes I do have plans to replace this and the particle effects with artwork that matches the other changes.
With the camera, there is a "center camera" button if you're playing with a joystick or gamepad, otherwise the mouse is used to look around and steer the aircraft. It is possible to fly with just the keyboard, however it's pretty hard to aim like this. I could add a keyboard binding to center the camera if that would help?
There will be further improvements to the damage response, but at this point I'm not 100% sure what that will look like.
Thanks again for your feedback.