Overall i enjoyed the campaign but looking back there were several things that bothered me about it; making a mistake and having to restart the mission and how long certain missions were.
Implementing quick saves and decreasing the length of certain mission is prob a good quality of life improvement that should be added.
Add 2 quick saves that go off at certain points in the mission with the ability to load last quick save and the one before that. having it quick save whenever the map increases and whenever an objective is completed/or added quick save.
A few missions felt pointlessly long (i played the campaign on hard and i quickly skimmed through a lets play by serious gaming to remind myself of which missions were too long.
A few missions that were too long:
mission 2 Gorgutz big gun mission after the gun moves backwards for first time double or even triple the speed at which it charges
mission 3 decrease gitstomper's hp by 1k. the fight didn't seem hard only time consuming.
mission 5 he keeps says no change every 5 sec stop it, some times i want to capture points. Defend workshop seems to be defend for 14 mins or so. change it to 8 or 10 mins
mission 12 the tracker beam should only 10k hp its too tanky right now. in my play through i had all my units gained from the map all alive, lost a few models of my assault marine squads
mission 13 +50% the speed that is required to repair the wraithlord, or let multiple repair points be interactable from the start. this part of the mission takes around 10 mins.