The concept here is pretty fun. I do like flying games and I like your implementation here. The game overall reminds me a lot of Luftrausers which I'm not sure if it was an inspiration for this or not. Visually it looks really good too. You marked that you've used pre-existing art but I think you've done a good job at putting it together in a coherent style. I think it could make for a fun full release game if you choose to work on it more. One thing I thought would happen which could be another transformation suggestion was the rocket not having any thrust and just falling down so having to predict where it will go before you transform.