Thanks for playing! We never got to do sound because I was completely occupied 24/7 with coding things that were new to me (like voxels and world generation). Given more time, I would have 100% made more sound effects.
During our testing, we actually didn't have much of an issue with enemy spawning. You only have to use enemies as platforms to progress in about 10% of levels; usually, walljumping and ghost jumping are sufficient to reach almost any destination, and worst case scenario a single burst from the jetpack will more than make up for an enemy stomp. I hope you discovered the walljumping mechanic because we never stated it in game, and some of the people who we showed the game to didn't know they could jump off of walls!