This is a very balanced and well-executed game. It has a well-written story, variety of gameplay elements and areas, fits the theme, and seems to suffer from no major bugs or breakages.
The main annoyance I ran into, that made it hard to complete the game without resorting to cheating, is how unforgiving the parkour sections are, especially considering the level of movement jank in Minetest. It was hard to get my momentum correct client-side but lock in server-side, even with the short network path for singleplayer. Something like allowing you to set restart checkpoints by standing perfectly still for a few seconds would have been more fair, without sacrificing the challenge for people who want to speed through.
The projectile combat also felt a little sluggish, though this may just have been my bias coming from other games with faster-moving projectiles; given the movement speed of the enemies, it didn't feel unfair or anything. I didn't have enough health supplies for the boss fight, but apparently the only consequence for dying is injury to my pride, so you can still make it through even if you didn't plan well enough.
I didn't find the plot twist all that surprising, but the evolving gameplay supplied enough intrigue to keep me interested through it, and the story was at least not a distraction, and gave the gameplay a sense of structure and meaning.
Players should expect to need some patience for the parkour elements (especially with MT's imprecision) but the momentum-locking mechanic makes those still worth experiencing, and the game overall is enjoyable in a single sitting, and for replay value you can speed-run it.