As someone who started playing from 2018-2019, I want to give my view on things.
I like the version before starting elements was implemented, giving the game a very simplified state. At some point, with only a few unit at 4 STR gene which you get from random stuff, you can attempt to end the final battle with it. Tsunami especially feel very nice, but the game tutorial is also barebone so mostly I didn't do anything except fucking around in those versions.
The biggest game changer update is probably version 0.17. You have a new final ending. You have more etc. You are actually motivated to build a decent team or else you would get nailed. It's probably the perfect version.
There are many incremental change since 0.17. Personally, I hated the whole dating stuff. It just goes on and on.
What really changes in recent times is Syvaron changing up entire gameplay mechanics. Before, you were just adding new mechanics, new complexity, or even switching character skill around. Now the game tries to reinvent itself. It feels as if Syvaron cannot leave well enough alone.
Tho I must admit if I started with the new version I probably wouldn't have that complain. It's only because I started with the old version that I am uninterested in how the gameplay changes completely.