I kinda don't understand this one, I played for like 20 minutes and feel like I got pretty far (because the glasses upgrade is busted since it gives like 6x your money for such a low cost haha), yet I never had any opportunity to get a single green gem for the persistent upgrades, at least not that I saw. I picked up a lot of orange gems though that seemed to deliver some lore but not too much else? It did take me like 15 minutes to realize you can scroll up/down in the upgrades section so maybe I just needed to dig deeper into those bottom upgrades?
The art is nice, especially the animations I'd say. But the music does not loop for very long, it only lasts a couple of minutes and then just stops haha, definitely worth looking into fixing that bug as the game gets kind of monotonous quickly, especially with no music
The sword swinging animation locks you in for a really long time, unable to jump or slide - that means you have to avoid all the enemies entirely or else you will eventually come into a situation where you are swinging at a line of 2-3 enemies until an obstacle comes along and it's impossible to dodge it -- that's pretty frustrating