They actually made all the assets from the ground up iirc. That's a mistake imo. The problem isnt the map design (believe or or not they are still pretty good, but lacking the variety elex 1 had)
However the art direction is a step down from elex. Everything is higher fidelity and detail, but (including the nightmare faces) they look like a downgrade from elex
The main problem is the technical issues it released it, more shallow faction and interaction. They sell it as having more choices and going independent like new vegas, but the factions are shallower than elex 1.
The story direction is completely fucked up too. They never had high brow story but the beats of elex 2 is awkward.
The combat is actually shallower than elex 1. It's my main beef with the game. In elex, jank as it is, the combo timer system is interesting, as it build up, allow you to perform powerful finishers, etc. Elex 2 use the tap for light attack, hold for heavy attack and stopped there. They took the most interesting thing about elex 1's combat instead of improving it.