A beautiful and exceptionally well-crafted short adventure with a very fitting and satisfying conclusion. I think it perfectly embodies not only minimalist graphics or gameplay, but the spirit of minimalism as well. The visuals were lovely and the music was quite fitting and serene, and I loved the variety of weapons and enemies. It really felt like there were multiple ways to deal with each room and encounter, which is quite impressive for such a minimal game!
My only issues were that the orange enemies often ended up stuck in doorways, and I wish the warning for the larger enemies' dash attack was a bit more visible. Perhaps the enemy attacks themselves could be a bit snappier and more aggressive, too - as it stands, I feel like there wasn't much reason to use the player's own dash ability. In addition, I think the player might feel better to control if the hitbox was slightly smaller than the visible model. Also, the game crashed on my first time trying to collect the circle powerup, though fortunately this problem solved itself afterwards.
That said, those were at most minor nitpicks that didn't detract from the experience at all. And I'd say the implementation of the theme was hands down immaculate!