Fight the same enemies over and over again until you reach a high enough level to beat each plot mission. Each plot mission has the same enemies as the randomly generated missions. Boring. I only finished it by putting netflix on while I played. The game is very unbalanced with the Void Psyker being able to put out 10,000+ damage with ease in a single turn while other classes struggle to do 1,000.
Enemies have insane accuracy and a single shot sends your aim all over the place, even moving it by 90 degrees at times. What this means is that you have to snipe enemies from a ludicrous distance because if they manage to get a lock on you, you'll basically be stun locked because your aim will be flying all over the place and you'll be dead in seconds. All of this culminates in the escort mission "Midnight Munitions Run" where you have to fly through an ever narrowing tunnel filled with enemies while protecting another ship. If you take a shot from any of the enemies there's a good chance you'll end up flying into a wall and dying. If you go slowly then your VIP will fly on ahead in a suicidal charge and get themselves killed. The game has no checkpoints so it requires near-perfect gameplay for ten solid minutes. I even failed the mission with the invincibility cheat on because the screen-shaking stun locked me for ages and the VIP went on and died. The ingredients for a good game are there but good god, the baffling design decisions just make it an absolute slog to play.
The enemies in the game are essentially anchored to you and always know where you are which hampers the experience. In the end I found sprinting about like a mad man more effective than trying to sneak as you're going to encounter the monster regardless as they home in on your position. I bought this on sale and while it was somewhat interesting, I feel it wasn't worth buying.