Things I noticed after playing the demo for a bit:
Some kind of mention that the game tracks turns outside of battle would be good. I thought potions would be useless except in battle because I didn't know that the recovery over time worked and would happen as I walked around. It also opens up stuff like using a potion right before a tough fight so you get the regen without using a turn, that's pretty cool.
Along those lines, Lucid potion would be a lot better if it could also be used when you were outside of battle so you could bring status immunity into a fight. Don't know whether that would be overpowered or not, so if it was your intention to make it always cost a turn then I guess it makes sense.
Tried the 50% strength antidote ring and got poisoned with very high reliability, poison also did full damage. I don't know if my luck is just really bad or the antidote ring is meant to be used alongside the "inmunity" ring for full defense. Using the inmunity ring alone also does not seem to provide a chance to avoid poison.
Fake attack seems extremely bad. A 2 turn debuff where 1 turn is spent using the non-damaging skill seems like mostly a waste. Early in the game I didn't really face anything that needs a defense debuff to handle. Later on, considering how valuable TP is the moment energy claws are unlocked, I can't really justify ever using it.
As others have noted, the cave boss is a large difficulty spike compared to the other enemies in there. You've already noted that you will provide more ways to advance before you have to fight it in the full game, so I just want to know if improved food can be unlocked before the boss. I wasn't sure whether beating the boss was what unlocked it or not.
Now for some of the stuff I liked:
Energy Claws feels really good to use. It's cool to have a move like that which you can anchor your strategy around in most battles because of how reliable it is, where you can't use it every turn but you CAN use it every battle due to how TP works.
Most encounters feel pretty well-balanced, in that they are not easily cleared unless you're very over-leveled but there's pretty much always a way to deal with them if you explore your options. Good stuff.
Artwork is high quality as expected. Does a lot of work towards setting up the overall feel of the game.
And finally...
thanks very much for doing this, I hope you can keep going with this project because it already has a lot of enjoyable things in it.