I really enjoyed the pixel art on this one, in particular the exploration areas were amazing! I lots of cool touches like the reflective water, shadows, and nice parallaxing background! (Though the stars seemed to parallax oddly in some areas) Tons of atmosphere! Adding to that was the excellent music.
The transformation sequence was a great addition! The combat sections were solid, but I they didn't feel quite as good as the exploration sections, in both control and graphics. I believe you are planning to continue developing and polishing, so this is one area that would be nice to see updated! A little more depth to the player's attacks and controls would go a long way to make this section more fun.
The story was neat. Definitely gave me Madoka vibes. The character's matter of fact response to her plight and the "solution" was funny. (I should note, I played in English because I unfortunately can't read Spanish)
All and all, a really good game! And since you're continuing work on it, it can only get even better!