Notes as I play:
- Thank you for changing the default title theme.
- Nicely done credits with links.
- a typo in the very first message I see. We're off to a good start :)
- very mechanical intro, no lore whatsoever. Myself, I would prefer to get some kind of lore hook. Instead of "hey, this is my game, here's how it works, here's my twitter" I would rather get a very short and simple (even very cliche) something like "wow, you fell from the sky, hope you are alright, here's 10 trials that await you if you want to get out of here"
- tutorial embedded in the intro is too rushed. It mentions some Mystic, some Ninja and number of attacks at the point where all I know about the game is that we are in a grey room.
- having one character do 4 attacks instead of 1 is both OP and tedious
- was a bit weirded out when I had to push the action button to go to the next stage
- there's not much "special" about waiting if you catch my drift ;)
- I see absolutely no reason for manually restoring your party at the crystal since you will always do it anyway. This should happen automatically after every battle.
- I lost count of the floors. A counter would be nice. Just displaying map name. Just adding those names could add to the lore as well if they were creative enough.
- why do I have 900G? What for? :)

Summary:
Unfortunately, this game has absolutely nothing to offer. It is all about combat, but in the worst jRPG style: close your eyes and keep pressing the action button for 25 minutes. During the first 2 battles I was curious what the new skills are. Later, I was just spamming attacks, not caring. Up until the Vampires none of the party members even went into critical state. And, like in almost every jRPG from the past 30 years, at the very end of the attackfest there's a boss that first makes you cry when you look at the 20k HP you will have to click through and then makes you sigh with relief when at 25% HP he just one-shots the whole party because why not.

Advice:
Identify the core engagement of the game. Here it's not that hard. It's supposed to be combat. If that's all the game is about, make it good. Make it interesting. I would rather see a demo with a single battle that's interesting, where something happens. Where I have some problem to solve. Some puzzle. Anything, really. Look at games that did it much better: Final Fantasy 7's Battle Arena in Gold Saucer. It's still an attackfest but at least there's some risk involved in going further. Look at Teamfight Tactics from Riot: there's an element of randomness between the boring battles, adding to the engagement. Finally, look into Persona 3 to 5 - those are the only jRPGs I can remember having combat that's actually engaging and demands thinking (sometimes).

I am marking controls as the favourite aspect, because my "enter" key is nice and comfortable.

Hah, good luck with making it bigger. It's actually a very good development technique. You start with something small (10 rooms + 10 battles) and then start building on top of that. The great thing about this is with every demo you get a playable "game" not just a vertical slice of it. It might not be the best game. Might not even be good, but it's a game. Not a complete work in progress with visible holes.

One thing I forgot to mention was the fact that your game wasn't buggy at all. It had tons of issues, as pointed above, but dumb bugs weren't among them. Sure, there wasn't much space for those, but it's good to work clean.