I know this is a bit old at this point, I've been working on other projects so it took a bit, but as I said I would, I finally got around to making new levels for this, in order to finish out the prototype/vertical slice!
Posting here for any of y'all that truly wanted more content (added three more levels, rounded out what would be 'Chapter 1' of the game, and improved/polished some systems as well as creating some new ones)
Patch Notes available on the game page