I don't want to use gdscript, because I hate python.
I actually do know plenty about game development. And most of your argument about not using godot just boiled down to that statement I quoted.
I've done this dance, I'm a dev too, I'm not familiar with live2d so it''s not like I was specifically thinking of that, i was just thinking of the overall gameplay, i've seen far more complex games done with ren'py (there was this guy I remember who kept making dungeon crawlers in it for instance), it's maybe not out of the box made for games of this complexity but it's really not complicated to add what basically amounts to some stats in, and that stock trading minigame too wouldn't be hard, i've seen more renpy games do just that than I have seen renpy games not doing it actually (but that's somewhat just my preference for games with numbers that go up I suppose).
Your attitude towards gdscript and python is harmful to you as a developer, sure it's fine if you're just on unity, but now that you're in the market for a new engine, keeping your mind so closed to new languages is not doing you any favors. gdscript and python are really easy to learn, they're scripting languages, there's no real logical reason to hate either of them. You can learn gdscript in a day, python is much the same really so long as you have a background in other languages. Like C#. These are tools, you don't see many mechanics refusing to use screwdrivers because they prefer wrenches, do you? that's basically what you're doing to yourself here.
Someone is working on a live2d implementation for godot, I did look it up since you mentioned it. But I know you can't do much with that, I've been there too, in fact I stopped using godot myself and switched to unreal for the same reason (IK didn't have a working implementation in 3D in Godot; game I wanted to make wasn't possible to create without decent IK). Godot is really easy to extend though so if you were really determined I'm sure you could implement it yourself in a few weeks.
It doesn't work on the web version and has problems with android. Unity's live2d works on both of those.
Those are sacrifices we devs (or if we're bigger, the producer or publisher) sometimes just gotta consider, most devs seem perfectly content to support only windows, I applaud you for going the extra mile to support everything (it was the first thing I said when I saw this game too wasn't it?), but how important is it to you really to support absolutely every platform? And how does that weigh against your demand for live2d?
You've clearly gone through all this before, and picked unity, and I am definitely not saying you should switch engines now, good god no, not this deep into the project, just finish up in unity.
But there will be a game after this, won't there? And unity is looking like an increasingly bad option is it not? And you make 2D games, your choice is most likely going to boil down to godot or renpy. Sure maybe you'll go for a more obscure engine like haxeflixel or something, but the point here is, there are other engines that could do what you've done here if you're going to ditch unity (which is the sensible thing to do, I don't remember the exact details but earlier this year I was going to make a game in unity, then there was some kind of scandal of a similar type to what we had just the other day, and I decided to steer clear, lead me to godot, I liked it a lot actually but it's IK system was broken so I couldn't stay with it, lead me to UE, Epic Games is a lot of things, most of them bad, but at least they seem content with their business model and aren't gonna do weird shit like unity's been pulling anytime soon. UE has been their main product since the 90s, the only real difficulty is that it's a complex beast of an engine and requires you to get cozy with C++ eventually if you plan to make a serious game on it)
Also don't get too hung up on live2d, it's a convenience, but we've seen sex mechanics like this since the days of hentai flash games in the early 2000s. It's not the only way to do this even if the results of it are surprisingly nice.
Whatever the decision you end up making, I believe it's critical to have an engine you can trust, and right now unity is looking about as trustworthy as a snake in the grass, hissing in your general direction.
But do finish your current unity projects in unity, for your sanity's sake.
