As you mentioned, the game seems to be from Unitys own Survival Shooter. The idea to modify it to a "horror" shooter is a fun idea, but sadly it feels like its missing a lot of things.

The Bad:
- The camera angle is rather bad. Its first of way to zoomed in, as you seem to be able to shoot things outside of sight. The camera is also placed directly ABOVE the character, which does not make use of the 3D perspective. I would have rather seen it place at a slight angle so you can se the models better, with that you can also experiment having the camera follow/rotate with the player.
- The light effects are way over the top. The constant blinking is a issue.
- You need more sound variations for the hit-scream sounds, the constant layering of the same scream is irritating.
- The level-design seems rather boring and repetitive. I get that most survival games of this typ use even simpler level design (just a flat plane) but at least they usually have a interesting ground texture. You are already using walls, so you need some more things then you have to keep it interesting (pits, props, lights etc.).
- Needs more weapons and enemies.
- With this horror theme, there really needs to be more details to the death effects of the enemies. Right now they really just feel like harmless puppets, get some gore in there (flying bits, gore on the floor etc.)! Its the details that matter in game-feel.
- Might need a marker or clue that points the player towards the gate.

The Good:
- Seems lika a good learning experience.
- The level idea with the up/down walls have potential
- The light effects are cool, but might want to reduce the constant "blinking" effect. Seems to get rather irritating to play
- The colors fit the theme, needs better balance tho.