Thanks for playing and for your positive feedback! Really glad you enjoyed the game.
Removing the acceleration of time passage when in high speed is something we are going to consider, since it does feel too punishing at times. Turning it into deceleration though is unlikely since we were initially inspired by the fact that IRL, when you are going with speeds near to that of light, time DOES pass slower for you than for everyone else. So we probably won't turn that upside down in our game.
Lastly, as the music producer, thanks for the positive comments, I'm really happy that you enjoyed the music!