Alright! Since I've finished the demo now, here are my final thoughts (sorry for the double post, I figured since it's a completely new comment and it's been over a day this would be better as a separate post):
I really like this game! The worldbuilding is open-ended enough to allow exploration but provides just enough to whet your appetite for more. There's a lot of humour in the dialogue and the interactions between the characters are delightful, particularly between Dorothy and Ria.
I concur with what everyone said about the music; the tracks have all been very well chosen for their purposes and there are some total earworms in there. I quite often have my sound off when playing RPG Maker games but I kept it on as much as I could for this one because the music was awesome.
Dorothy's mechanic is the most intriguing, but also potentially the most problematic, for reasons I'm sure Ouro knows. I love the Blue Mage+ concept, and the fact that you learn skills just by observing them rather than needing to be hit by them. There are a huge number of skills to get: in this demo alone I've learned 112 and I'm not sure I have all the ones available. It's cool that there are set schools of abilities, and each character besides Dorothy is limited in which ones they're able to use.
The main problems with this are balance and redundancy. Allowing Dorothy to learn absolutely every skill used by an enemy is fraught with balancing issues, because what's not all that powerful for an enemy to use every so often becomes a huge hammer when given to Dorothy and a human player who can decide when to use it and what it's used along with. The fact is that a lot of the skills you can learn will never see the light of day, some are only really useful for summoning hidden bosses, and some just plain don't do anything the party can make use of. (I'm looking at you, Royal Jelly...)
This results in a rather bloated ability screen where I was constantly scrolling to get to what I wanted. But don't get me wrong, boy were there things I wanted. That brings up the next problem: broken combinations. When I got Euphoric Tome, it essentially meant that other party members no longer had resource costs for their skills because I could get back anything they spent, be it HP or MP. Slime Dance Music allowed me to supercharge everyone's TP really fast, and I had Knockknee Jig for Dorothy if I needed to get TP back for just her. One I outfitted Ria with Cheerleader, that and a few turns of Overclock made battles outside of bosses utterly trivial. I highly recommend that Ouro adjust Overclock's cost to a percentage, because later on 20 HP and MP are nothing. I also recommend nerfing how much healing and MP recovery Cheerleader does, and raise the TP cost of Euphoric Tome. With this power set at this point in the demo, making any non-boss battle in later updates any sort of challenge will require some serious cheesing of mechanics and it'll probably be less of a headache to make sure the player isn't a god before even entering Kallech.
I honestly didn't have as much of an issue with the encounter rate as other players, especially since running away never fails (I also love that it's called "Flight"), and there's a sceptre you can buy in the tower that stops encounters entirely, which is useful for some of the puzzles and exploration maps.
That does bring me to another potential issue: there's a very easy way to make infinite money, and again it trivialises some content by allowing you to just buy however many of any item you want and get every tome the random lottery has. And since the tower sentry encounters automatically end if you have the sceptre equipped, that's free exp and money you can use to start off the chain. I recommend modifying the encounter that happens if you have the sceptre equipped to one that doesn't give you money or exp, and also reduce the profit margin of selling potions to the guy at the lake so that it's more of a slog to make ludicrous amounts of money from it. 100g profit per item is just too much for me not to take advantage of.
There's a lot here already for a demo, and I will absolutely be on tenterhooks for the future of this project. It's been a while since I was so excited about an RM game, and I genuinely think this is on par with some of the greats like NigSek, Master of the Wind, The Way and Last Scenario. There's so much attention to detail and some neat little aspects I've never really seen done in RPG Maker before (like having a feasible plot-related reason for the RTP forest tileset's trees looking so terrible). Ouro is a talented developer and has made a game that I think will generate a lot of interest when it's done.