ATV audio for acceleration is wonkey, it should have a smoother transition. for example if you tap acceleration you can hear the start of the audio clip in a harsh way. The audio should have a rise to max rev. If that makes any sense.
Dr. Kel needs to have like a 6th sense instead of [save: NULL] indication. An audio cue or the character voicing that "something doesn't feel right."
Some examples could be:
Heavy breathing, breath fog , a quiet heartbeat, scratching noises, directional whisper that makes you turn in the direction of an entity you shouldn't look at [don't look reference], screen effects depending on the entity like tunnel vision, inverted colors, or vision like you are looking through a broken mirror with it's slightly off plain of view.
Making the moon bigger is a good idea.
You can put a Majoras Mask reference with this suggestion too. I never played it and yet the image still freaks me out.
It would be funny if you can change the moons reputation based on how much cheese you eat.
A Trip To the Moon reference possible (where the space ship crashes into the moon's eye).
Wallace and Gromit (a grand day out) references possible (which had a coin operated murder robot in it)
I think using AI music should be considered or even used as a starting place to add more music. Suno.com
ie use AI to create the song and then pay to have it recreated by a musician on fiver or something. I am sure Patreons have skills that can be donated.