I can see this game is a piece of fine art in the making, so my following recommendations might directly conflict your vision. Regardless, here are my thoughts as someone how finish the entire demo.
Gacha life seem to be your bread and butter and I think it was used to great effect. Elydas and the spirit is visually appealing, and the blank "characters" are unnerving to look at and would make a great enemy moving forward. One gripe I have is that B didn't look scary enough? Intentional or not, the face looked more hostile than scary.
The character moved too slow, to the point that I often let Elydas "die" to teleport him to another end of a room.
I know this is supposed to be Elydas' house, but the set pieces are rather one note. They are either pink or blank white. The outdoors segments did help shake things up however.
"Time Stop" is powerful ability that keep Elydas out of harms way and you already explored a bit with this mechanic. I would like to see more of this in the future.
The tutorialization is excellent, players will most likely learn how to "Time Stop" before learning how to move. Having prompts on the bottom is also a plus.
As someone else in the comments pointed out, a proper inventory system would improve the game quite a bit. The pacing of the game is well enough that it somewhat covers this issue, but I can see someone affected much worse.