Definitely enjoyed this demo. Gameplay is fun and I can definitely see how it could be expanded upon with the inventory (and class?) system. None of the enemies or bosses were particularly challenging, although they did take some careful consideration of their patterns. The platforming itself works well, although the walljump needs some improvement; it works only half of the time and for a large part seems to ignore my imput, no matter what I try. Another criticism with regards to platforming would be falling damage. While there's nothing wrong with it (especially since the double jump cancels everything out), it would be nice to give some sort of indication of taking damage, as it can really sneak up on you without you noticing.

There are some glitches here and there, where the character is almost magnetically drawn to a certain area or platform. On one occasion I got stuck in a wall, and on my latest playthrough, the game crashed at the final boss.

Overall an enjoyable experience, I'd like to see how you will implement the RPG elements in the future and how choices such as saving/killing your sister influence the narrative. Love the fact that there's an optional path with an extra boss, giving you a bonus item. I definitely hope to see more of that in the future as well.