The new demo was something I've been anticipating for a while and it didn't disappoint. I really enjoyed playing through it and finding all the new forms. If you do continue working on this, I think you should add more bad endings instead of scrapping them. I really liked finding them and seeing what happens to Nana.
The only two things I had issues with were that the golden retriever bad ending doesn't have the bad ending indicator even when it's turned on, which makes it difficult to find because there is no indication that the gold chest in the forest triggers the bad ending otherwise. The other main issue I had was the balancing between the different forms (specifically I think the wolf form is a bit too good and the golden retriever form needs a slight rework to the playful meter). If you hit 20 stacks on the playful meter and get overexcitement then there is no guaranteed way to get out of overexcitement. I feel like overexcitement should have a cap on the amount of turns it lasts, there were times when I'd not get out of it until about 7 or more turns had passed. Also, I don't know if this is intentional or not but for some reason using a party potion with a party member also increases playfulness by 1? As for the wolf form, the boss fight for this form is a big difficulty spike compared to the rest of the game and I needed to grind to around level 17-18 playing on normal in order to beat the fight, which is a way higher level than the other forms I had unlocked up until that point. Combined with how good the wolf skills become at night and I felt inclined to use the wolf form for everything outside of when you're forced into other forms. Then again, I did unlock the wolf as my fifth or so form so maybe I went to it too early, but I still feel like it's better than every other form in combat.