So after sinking in -jesus christ 14 hours- here's my mini review/comparison. If you've never heard of/played Elona, watch Sseth's review, it's too big to go over entirely.
Stuff missing from old Elona (modded with plus):
Bunch of feats (to be fair a bunch of those were crap, and there are some new ones)
Limit break system for melee weapons
Seems to have fewer/very few unique quests, though maybe I'm just not finding any.
No trade goods mechanic? (Probably for the best, but musician is still in so maybe trade is coming back) I think the blackjack is gone too, but the slot machine is in? Didn't test much.
No more ether wind? Haven't seen it so far at least.
No more bell enemies? Unless they show up later.
UI is a bit shit, it's lacking full keyboard control and I frequently end up fumbling an item out of my inventory when I mean to do something else, even in combat.
Stuff that is new/expanded:
Crafting system that actually seems pretty good. Though I'm having a hell of a time getting blacksmithing rolling; it seems some skills are meant to be starter skills and blacksmithing isn't one of them. At least I don't need a fucking microchip like the glassmaking...
Quality of Life features. Dear god, I'm never going back. You can search for items on the map and it includes chests, so you'll never misplace something in your 30 chest hoard of crap. Auto stashing loot when you get home. Auto pathing and watering crops. Automatically praying once a day (that costs a feat; totally worth it.) Auto combat done in an intelligent way with customizable settings. Auto pathing to the random quest givers or people you ask the guard the location of, including specific merchants or the quest board etc.
Races/classes have more unique mechanics, especially the advanced ones. You can be a succubus and get stronger by boinking people, apparently. There's a wraith that uses mana as health. Dwarves get stat buffs from booze. Cool shit.
Bunch of new areas. Probably less than Elona+ had, but I haven't got far enough in either game to make that call.
3D isometric perspective. Actually not a fan; it looks good 90% of the time, but then once in a while it hides a chest behind a tree or you go to Derphy and can't see fuck all in the slums. Hopefully there's an option to hide roofs at all times.
Summoning spells seem to be a thing? There seems to be a separate stat for summoned minions besides companions. Potentially very cool.
More job board quests I think, especially combat oriented ones. You can get passive ones like 'just kill X monsters over the next 2 weeks' which is nice.
There's a whole complex town creation system with jobs and laws and research and shit. Haven't gotten deep in it yet but is potentially very cool. It sucks at the begining; lots of tutorials and there's annoying shit like weeds and trash appearing randomly in your base until you level it up.
Shrines in dungeons, that do stuff like summon a boss, upgrade an item of your choice, and other cool shit.
TLDR: It's really good, I prefer it over the previous game despite missing features. If development keeps going and it adds more stuff it'll be my new favourite roguelike, which is a tall fucking order. And it's still got slaves and child murder and whatever, hasn't been hit with the PC stick. Though if you aren't paying attention in character creation your mom might be a begging cuckold.