Thanks for playing! I originally planned for the Space Walk level to be the last out of four. It's basically just offbeats.
This really helpful article by Yu Chao on Gamasutra provided me with a seed:
https://www.gamasutra.com/blogs/YuChao/20170316/293814/Music_Syncing_in_Rhythm_Games.php
For my project the important part was the array of beats and finding a way to detect input in a fraction of time around those beats. It helps to have your song in a DAW to see the percussion layer and base the point in bpm of beats around something on that layer. In the Space Walk level I used the snare. If you're composing your songs you need to be mindful of which instrument you're gonna base the input on, it's part of the level design.
