Fun Metroidvania, played it a couple of times and got 100% under 9 minutes. Personally I really apricate the slight delay from pressing the attack button and the attack coming out. It's like the Castlevania whip in terms of length and serves the same purpose of making the attack feel like you are attacking with something that isn't a natural extension to the player making it feel natural for the visuals. I liked how Ray was mostly used mostly used for puzzles rather than combat as it kept Boxer form being useless. The level design for the most part excellent. The figure 8 design made the exploration fun and the addition of more enemies/obstacles as you did backtrack made older parts fell fresh, especially exploring with Coil.
I do wish that Coil would stay out a split second longer as the sort length he stays out is a bit jarring the first couple of times you use him, but you do get use to it. Also the game would of benefited from a wider screen IMO, like the 4:3 retro resolution is fine for aesthetic but it does make some jumps uncomfortable. Namely the string of mushroom jumps over the lava pits, and more over the jump on the second floor where you have to jump down to the mushroom with the enemy walking in front of it, because you don't know how wide that platform is and if you jump with him offscreen he will know you down the the first floor. Also encountered a small "bug" where I deployed Coil and kept the momentum with hurt animation as I bounced off Coil covering a lot of ground.
But an all in all fantastic experience that would of fit squarely with any NES game in terms of gameplay and style. Really fun to play and a charming overgrown landscape to explore.