Hmm, never thought I'd fly through space by controlling the planets, but here we are.
Creative concept, great execution. Balancing putting planets close to the "player" to get better control while not smashing into the planets leads to surprisingly naturally balanced gameplay. Game is fast enough to be challenging and fun without being so fast that it feels unfair or stressful.
I generally try to give a point of constructive criticism when critiquing games, but I genuinely don't have anything to say except well done, and good luck!