Chaos Gate Daemonhunters isn't a bad game.
I'll start with the cons:
The story. It is being let down by the fact it is 40K. Greyknights are simply not engaging protagonists, just like most space marines. For 40K fans the story is great. The premise is suitably epic. The adeptus mechanicus dominus in charge of your ship's maintenance is well written. It seems 40K writers like the adeptus mechanicus to lighten the grimdark.
What makes less sense is how you get reinforcements and equipment sent from Titan. The Greyknights send a single, small shuttle with a single knight and a spare storm bolter? That seems silly. In that the old Chaos Gate did better: you had a roster of marines on board, and that was it.
I can see how people can find the game getting repetitive. On the one hand you only fight Nurgle. Even though attempts have been made to give your opponents a large roster, it doesn't change that they all are Nurgle.
On top of that, the maps start to repeat. A few of them add insult to injury by basically being a pretty corridor, with no choice but to advance down one single path. And there seem to only be two mission objectives.
Last con: the soldiers just aren't memorable. Firaxcom managed to make you care about your troops and remember them, even though for the most part they were random grunts. Phoenix Point has the roster grow so fast, other than maybe your first squad, it is unlikely you'll think of any of them as anything but sniper, commando, heavy etc. Chaos Gate is the same, your marines are melee dude in terminator armour, melee dude in power armour etc, even though you may count your troops using your fingers.
The pros:
Destructible terrain makes everything better. Lots of bits to interact with to kill your opponents makes it betterer. If your opponent is hiding behind a statue, it is very satisfying to slam into the statue and bury them underneath the rubble.
Enemy variety is actually quite good, even if the focus on Nurgle gives a feeling of repetitiveness. In reality though there may be more variety than XCOM.
Boss fights seem to be thought out. I have done two big story missions. The first one had a good premise but was a bit let down by the Greyknightytness. It makes sense and allows for super fans to have some fanservice, but for the rest of us it's a "if I cared I guess I would care" moment. The second one was tough as well, but I beat it by using my marines abilities well, while realising there was a smarter way to do the mission. I like that: a boss fight I could beat two ways.
Stuns/crits/Knockback etc all work quite well and give you some tactical choices. Crits are pip boy style targeting and make for some grotesque funny situations: stop an opponent from shooting their gun? Chop their arm off and disarm them. If I were the opponent I'd be dead after that, but people in the game are a bit tougher than that.
Skill trees are quite large for this kind of game, so you could tune your marines the way you like. And with 8 classes you get to tune your 4-man team.
Bloom actually works reasonably well as a mission timer. It increases every turn and every special ability you use. Later you may be able to reduce it or limit the passive increase to gain some breathing room. But it isn't a mission failure timer.
It isn't drawing me in like Troubleshooter did or any good story based game will. I don't feel the need to fire it up to see what comes next. But when you have it launched, you may want to go for just one more mission.