For us, the biggest problem is how repetitive and basic Space Hulk: Deathwing is. You can get bored really quickly in solo play of Space Hulk: Deathwing as well.
Space Hulk: Deathwing is an expensive shooter but doesn’t offer a lot
You can only carry two weapons (or one) but you can’t switch weapons unless you waste a Psy gate. This is also tied to medkit charges and respawning your teammates. If you had the storm bolter to a default third slot like Space Marine did it, it would be better. Ideally, the game would allow you to switch between teammates so you could try out all the different guns
You can’t really do anything with the environment. Sure you can “hack” turrets but we rarely found the case where enemies were already out in the open and we could take care of them. Plus if an enemy attacks you, you get interrupted. A better way would have been the option to permanently make a turret attaXenosnos. And while it’s nice that you can lock doors, we would have preferred if you could permanently close off SOME of the Tyranid spawn points. Like those huge open hatches.
There’s no reason to explore since you don’t find anything valuable. Relics boost your XP and give you a Psy gate charge. But that’s not really worth slogging through 50-70 genestealers who respawn infinitely while you’re racing against the clock with limited resources. If relics gave you permanent bonuses that would have been a way better incentive to explore the needlessly complex albeit gorgeous maps.
We also have some other problems like the AI being really stupid at times. The game resets your loadout for no reason as well as long load times. But really the game is just boring. Shame too, because we love the 40K universe and really want a good 40K FPS.