I had fun! Thank you for putting this out there. I thought the mechanics would get old after a while, but the pacing is perfect, and engagability stayed super high.
A criticism : Having Head Start delay the Refract currency gain the way it currently does makes sense - otherwise a few levels of Head Start would equate to infinite Refract points! But going from 66+ Refract on a full playthrough to 15 or so is a huge setback. It's a late game issue, possibly a post game one, but if you decide to expand the game further you may want to look at it. Maybe have Refract delayed like it is now, but have its income boosted such that it hits its previous high when the player gets as far as they had been previously?