It's fun. It is a very good peek at the universe, pretty much every situation can be resolved as a nice guy, imperial hardliner, or heretic.
It's owlcat so encounter design could use some work. Leveling is a little weird too. For the first act you level so fast and there are so many niche talents that it's easy to get overwhelmed. It gets a little easier when things slow down in act 2.
A few things are massively overpowered. If Argenta (your sister of battle) specs into arch militant, then congratulations, you are winning. Cassia, your navigator, has a unique set of moves available to her that wildly synergize with her class and are also extremely overpowered. For instance, she has a massive target able ground aoe that forces all enemies to move towards a designated point. Also all enemies that move take damage. Also you have aoe abilities that can apply debuffs and do damage you can follow up on that with. Also you grant your other companions extra moves. Essentially group them up with cassia, give them warp AIDS, then have her buff and give extra turns to Argenta and its DoWI BEHOLD THE IMMOLATOR time. It's actually very satisfying.
The characters are fun who you deal with. The banter can be witty. Your companions include your senseschal, who you can instruct to introduce you to everyone which is great. An interrogator of the inquisition. An unsanctioned psyker. A sister of battle. Your navigator. A wayward Space Wolf. An Eldar, if you're a xeno-consorting heretic. A dark Eldar, if you're a retarded xeno-consorting heretic. A tech priest. A couple random people. There are a few somewhat hidden companions as well.
You'll have plenty of opportunities to interact with your companions and if you're a dogmatic sort you can just eradicate the foul xenos right away. And you get a lot of chances to off that unsanctioned psyker!
On higher difficulties you can lose an initiative roll and get gibbed before you even move, literally at times. It's rare, but can happen. It happens less later on.
Space combat is lame and shitty and early game it's very lame and shitty. That problem where a bad initiative roll really fucks you can come to the fore quick there. Honestly it needs a rework.
The overworld design is likewise a little odd. A lot of loading screens to dance around a lot of star systems that may have nothing at all to do in them.
Honestly it's better than I expected but the further you go in the more bugs you'll find. It really wasn't all that well play tested in a lot of spots as you get further along. Most bugs are annoying rather than gamebreaking, or something weird like your abilities appearing greyed out but you still have actions available and can still use them as normal.
Difficulty level is reasonable, outside of some serious occasional rng fuckery. But again there are some really broken talents in the game and they will carry you hard. Like wipe the map in the first turn or two carried hard.
If you like 40k you will like it. If you don't like or know 40k but you like crpgs you'd probably still like it, but less so. If you don't generally like crpgs but are coming off a baldurs gate 3 high this is not going to scratch that same itch.