This game has a pretty great groove! The neon outline artstyle, light animations, poppy music and sound effect, and cute dialogue comes together for a smooth experience. We cleared the game and generally had a good time.
It's neat how the design leads to a sort of, optimization problem. It's all a math puzzle of how hard can you press yourself. The design space for that is limited, which makes it a pretty good jam game; there's no room to outstay its welcome, and this is about as far as this pleasant idea can go.
The specific numbers are a teensy bit awkward, though, and items don't feel terribly rewarding to play as. We tried a silly build where we pack-ratted away a whole bunch of Firecrackers to use in later levels, but it didn't quite come together. Getting the fancy sword for 50 Crystals right away, and basic attacking through all the encounters, just sort of feels like the way to go. Still, even if the numbers didn't add up perfectly, the presentation was interesting enough that we played through twice just to see if it'd work, and that's a lot more time than we've put in to some other games in the jam. Well done!