Honestly this was an underwhelming game relative to how glowing most of the reviews are. The combat, while cinematic, becomes monotonous very quickly.
Really should have had some jump/climb feature to get over small obstacles. Getting stopped dead in your tracks because of a small gap in the floor really makes space Marines look weak and breaks any semblance of an immersive experience.
For a game where you play as the nominal lieutenant of a squad, there are no controls whatsoever to direct the other space Marines you supposedly 'lead' - it would have been great to be able to tell them to follow/wait, move to position/hold position, enter melee only/ranged only/mixed stance, etc.
There are no choices to make whatsoever. The game is 100% linear, which really makes you feel like an irrelevant passenger rather than the lead protagonist.
The audio mixing is awful. Can hardly hear let alone understand all the dialogue, as it is not mixed to be louder or more in the auditory foreground than all the other noise. If you walk by NPCs who are having dialogue while the story dialogue is happening you'll just hear both at full volume. The effects they used for chaos voices make them extremely difficult to understand.
Level design was painful. Can't tell you how many times I approached a door or obstacle and couldn't pass, so I'd run off to look for alternate routes only to realize that the route I had been at already was where I was supposed to go, I just got there too fast and needed to wait for a time-gate. One level in particular, towards the end of the game, had me in a seemingly infinite black void - but actually there are invisible walls. No indicator to show me where to go, just wandering around for ~15 minutes until I suppose some time-gate was passed and the story kept going.
The writing was one note - every space marine basically is the same character with no individuators other than their appearance and slight differences in their voice. While yes, they're all space Marines, there could have been better writing to provide more depth to each named character, to say nothing of just how few named characters there were.
During the last scene, when talking. Tot he chaplain, camera kept zooming in right up into the guys armor.
For an IP with such rich lore, they really did explore it much. Cut scenes between missions were brief, a few lines and then you're back to the next linear mission and monotonous combat. They could have had much more dialogue exploring the lore.
Sad to see that this is what's hailed as a good game now. This is what happens when most of a studio's efforts and resources go towards graphics I suppose, and not nearly enough in writing or game mechanics. Especially noticeable in such a linear game.