Most important in my opinion: Balance the game based on the number of players in the game (this game is utterly ridiculous on your own) - Why wasn’t this done in the first place?
Fix the plethora of glitches - stats resetting, mission objective items not appearing, mission enemies not appear, having to jump, falling through the ground, enemies falling through the ground.
Levelling up is glacial. I’m around level 10 and it took me 500-600 machine kills (I don’t know exactly how many because my stats keeping resetting) to get here.
Have an ‘adventure mode’ option and a ‘hand holding option’ instead of having adventure mode as the default. Adventure modes are great but the way it’s been implemented here is not good. Often you get maps which are a different scale to the main map to find things, made even more difficult by the fact you have to navigate to the log, specific mission and specific mission item then to go back to the map (rinse repeat) until you can work out where you’re supposed to go. You also get missions with hints such as 'a note from person says that something happened at location. If you are going to have hints like that location has to DIRECTLY CORRELATE with the location names on the map. It’s no good giving me a random fictional Swedish location as a hint unless it’s one of the ones written on my my map.