Amazing job man, congratulations ! This is so impressive you did all that yourself, but very inspiring. I am also making a game on my free time but I would never be able to do everything myself like that.
The inventory looks nice, basically everything "feels" and looks very good ! Also we can feel this project was made out of love and passion, there is so much details into it and although it is only a demo yet we can feel the depth.
I can't imagine how hard it must be to design good puzzles... if too easy it gets really boring, if too hard very frustrating. I felt like the puzzles were all good, not very hard but not too easy (which is good for a not so into puzzle games player like me). The only puzzle that bothered me was the door one. It is fun to do the first time but there shouldn't be this advice from Keu I believe, to match with the mysterious puzzle atmosphere of the game. And then after the third time it gets boring to do. Maybe if that was more challenging and with a risk / reward thing that would work better ? Like if you fail to unlock the door in a certain time you can't open it anymore or you lose life, or something like that.
Even if usually I am more keen to play action packed games, I am really looking forward putting my hands on this one and it looks like there will be some good fights to satisfy my thirst of blood anyway.
Congratulations again ! <3