I honestly think it will just come down to the argument that "I'm nitpicking." However, I'll oblige:
The game uses simple shapes. You tend to use a lot of simple shapes in game development but you hide those with proper texture mapping. This game does neither of that and doesn't flesh out the world.
Texture mapping is atrocious in places. It tends to use a lot 2D mapping to create the illusion of 3D but doesn't achieve that result.
Uses 2D Decals for bullet shots. They can go beyond that or at leaast try to make those decals more believable. A lot of warping going on with bullet holes.
The game prides itself on killing but has atrocious gore and blood. Blood works in different ways. I might be wrong but why no blood physics? The engine is capable of that.. or at least make the blood believable. It looks comedic but the game isn't going for that appeal.
From what I gather it uses a limited amount of shaders. I can't be sure since it's a video but I'm not seeing a huge usage of them. They brag about pushing PhysX shit to it's limits. I'm not selling that. A few things breaking is not pushing PhysX to it's limits. PhysX can do far more than what they've presented.
3D Meshes for Guns and Player Model are pretty substandard. Lack a ton of detail. I dislike the animations of his Trenchcoat?
Which brings me to. The animations aren't great but aren't subpar either. They just feel average. If you are going for some executions maybe put some effort into those execution animations.
Aesthetically the game goes for this whole dark grimy grey outlook but makes sure dark reds and oranges pop. I'm assuming that is some artistic direction of the game. It's off putting for me. However, it's aesthetics so i'm not going to bang on it or consider it a negative of the games overall graphics.
With that said I'd like to touch on the mechanics. If all you do is kill shit with absolutely no purpose then to just kill then it's kind of shallow. Other games in this genre get called out for being shallow that offer far more mechanics. I mean will I be able to jump in a car and go run over people? Will I be able to flip that car in a fiery ball of death if I felt like it? What compelling mechanics are there that grabs the attention of the viewer?