A very relaxing game. Had a great time going through this. There are only a couple things I wish were different really, and one is very specific to me. Being partially red/green colour blind, there was a couple times I literally didn't see the eagles before it hit me. Not sure what would have worked within the single colour sytle you were mostly using but something to be aware of. The other minor point is I found the effects a little loud, distracting from the music. I wish they had been just a little quieter.
All that said, I did keep the game open the whole time I was writing this, listening to the ending music. I really did have a a wonderful time in those skies.