I really liked the demo, here are a few things that would help enbetter the experience:
1. Since time is frozen when examining items the text should be displayed immediately.
2. There should be some indication of what was picked up for repeat pickups (i.e. 2nd medkit or 1000th handgun bullet)
3. There's some sliding when the player stops. I would recommend zeroing the player's velocity when they enter their idle animation.
4. Gibs from an exploding locker (for example) can look like pickable items when highlighted with the flashlight + explosion light. Consider effecting how much they can be lit up or desaturating them somehow.
5. Give the currently targeted pickable item a different/stronger highlight than the other pickable items. If there are two identical items on the floor right next to each other ideally the player would know which one they're being prompted to pick up.
6. Targeting items for pickup is a little janky. It seems to be based on player position more than where the reticle is pointing at. This can make picking items by aiming at them or picking items up on high shelves difficult.
7. The roll is a little janky since you can freely slide around on the ground regardless of the direction the roll animation is going for. Consider a more strictly determined way of handling the roll animation's movement (like root animating it).
8. Bullet collisions can be janky. If the player positions themselves so that they're aiming at nothing while rubbing their right side up against a vending machine, the vending machine will take the bullet even though its behind the gun.
9. Enemy attack collisions are janky. Every time I was hit I didn't actually see the enemy's weapon make contact with my character.
Finally 10. The player character hangs to the left of the camera perhaps a little too strongly, centering him a bit might be nice.
This might be a lot but I only went through the trouble of posting it because I really REALLY enjoyed the demo and can't wait to see what the game looks like with further development! Best of luck!