Hope you don't mind lil criticism:
- Skyboxes are easy to find online and add. Typically you should use a custom skybox instead of the Unity default. Otherwise I would recommend a fog to hide the skybox (which may even add to the feel with the forest).
- I would recommend using 3D models instead of the basic shapes that Unity provides (especially with the trees). Plenty of free models online. Maybe you could even learn ProBuilder (a pretty easy-to-learn shape maker that works inside the Unity editor).
- I recommend texturing things instead of using solid colors. Makes it feel a bit less plastic-y. Again, easy to find and download.
- I don't see the puzzle element you described there would be? I kinda just walked into the wall at the end and beat the game. Like, none of the textboxes mattered at all whatsoever.
- The ending trigger looks like a solid wall, so some may thing it is just a dead end and turn around.
- You cannot actually press the quit button since the mouse is still locked from the FPS controller. You can fix this by making a simple that unlocks the mouse. This would either be triggered when you make the button appear.
- The eyes could be animated since they're kinda just static. I actually thought they were buttons at first.
- That was an unnecessarily long hallway and didn't really have any gameplay to it other than the W key.
I understand that you had only two days, but this is just constructive criticism to learn from. Besides, you can still update the game should you want.