I like the demo of Voice of Cards. The visuals are great for that tabletop/card feeling. I hope the game is harder though, as the fights were challenge-free.
I really liked it as well.
As soon as I finished it (and I don't finish most demos), I went to pre-order it right away.
It's essentially a tabletop game, with a lovely style (using that "gimmick" that everything is made of cards), and a very soothing, appealing soundtrack.
It felt to me like an older, classic CRPG, but with modern production values.
You are right that the demo was easy, but from what I gather it's a "prologue" that isn't part of the final game, so I assume things will be a bit more complex, and harder, in the final game (the screenshots I've seen appear to show so).
I've read plenty of comments voicing some "disappointment" at what the game is, mostly from fans of Yoko Taro, but as someone who doesn't have much affinity for his work (I only played Nier: Automata, so I haven't followed his work all that closely), I was actually presently surprised about the game.
It appears to channel the sense of imagination, and adventure, from tabletop games, and old text adventures/RPGs, but with a presentation that I found very appealing.