What I liked: A simple story with great execution. Especially at the end where the player has to make the choice to attack the spirit, rather than it being a dialogue option or something. The combat felt fun, and the audio was especially well implemented.
Less good: Readability of enemies and bullets was a bit hard, but ultimately fine. I was unable to beat the boss on my first run through, since a bug caused the red hurt flash to persist on the screen, making bullets very difficult to see.
Recommendations: Further incorporation of the sister into the gameplay. Buttons she can press, enemies whos attacks are directed at her, etc.