First, I will admit I'm not sure if I finished the game or barely started it. I reached the point where music starts and the credits appears, which could be an indication of either. The thing is that I hit pause and a single button labeled "Button" appeared in the middle of the screen. Curiosity got the better of me and I clicked on it. Turns out it's the close button... I started the game again but it didn't save my progression, so I stopped there. Please let me know if I was actually at the end or if I need to go back to it.
I will say I liked the glasses mechanic. I initially thought it was like the Lens of Truth in Zelda, only revealing hidden platforms, but it actually changes the world, which is a pretty nice twist and made for a few interesting puzzles. Though I would have liked a way to preview the changes they bring, as there's a few places where toggling them up will reveal thorns under your feet and kill you. I also got stuck inside a platform a one point when I materialized it at the wrong time. I could toggle it off to escape, so not a big issue.
The animations suffer a bit from the "paper doll" effect and the environments had a few visual issues at the seams. The parallax at the bottom of the first shaft confused my senses a bit. But the sound effects were really nice! They felt hefty in a satisfying way. Having some visual feedback when hitting the slimes would have been a nice way to complement them.
Overall it felt more like a pure platformer than a metroidvania, but again, maybe I only played through the intro? If you tell me there's more to it, I may revisit it ;)