Your usual fortes really shine through here; with the art, ui design, sound and player feedback all feeling really enjoyable. To be honest, as I'm not a huge fan of this style of game, I'd say that really nailing these factors (along with all the behind the scenes things like level restarts) kept me invested and playing until the very end.
But beyond your aesthetic achievements you also came up with something pretty unique and head scratching puzzler that forever felt fresh.
For me, the all important health stat number was a little too dull, often falling away from my immediate notice which was a little annoying as more often than not that was the only number that really mattered throughout my playthrough. I say that due to there being a whole load of ways you could simply gain infinite energy (by either spamming the duplicate or the add health to the energy cube). But fortunately even though that may sound quite gamebreaking to someone who hadn't played the game, the puzzles were made so well that having infinite energy often made no difference... they were still complex puzzles.
But within that perhaps there's something more inherent about the value of energy in the game, as it quite often became a stat which didn't really matter (at least for the levels you created).
I'm also never the biggest fan of big explainers to start off games; meaning that even though your wonderful art and sound led me through that early slideshow I couldn't help but feel that there was too heavy a reliance on the text. That left me feeling that there might be a more effective way to convey this information--perhaps through a little animated sequence or a purely visual slideshow that delivers the same narrative but without text?
Ultimately, that stuff's all pretty minor in light of the fact you managed to craft this really enjoyable, stylistically coherent and storefront worthy experience in just a few days... It's really astounding when I think about it!