I haven't watched too much of the full game, but what's the problem with the combat/ gunplay? I thought it was absolutely fine in the demo.
1. Dodge mechanic looks a bit clunky.
2. Melee weapon animations are limited and lack force visually
3. Lack of body hit reactions outside of visual marks
4. A couple of simple and rather bland boss battles, both being culminating arc fights.
Those are the inherent problems observed. People may also be referring to:
1. Lack of combat outside of the Bakers in the footage leaked so far. While I'm sure the enemies will be lacking compared to the rest of the series, the ship location demonstrates that enemy encounters increase dramatically further into the game.
2. Poor player skills in the streams, while the other available footage has someone with infinite ammo and foreknowledge cutting through everything. No happy medium that would be experienced by most here.