I see that you used this as an opportunity to play with the terrain tools, and I would love to see what you've done, but there is nothing gameplay wise driving me to venture around. I took the two photos of a couple random statues, I saw that they had a name and an occupation, but I struggled to find purpose in going to all the points of interest.
Your choice of asset packs works quite well, I would say they work together visually. Bit weird that the character runs with his palms towards his chest but that's not your design.
What I would change:
The control selection is horrendous. Enter to close a window? If I'm moving with WASD and looking with the mouse, it becomes an exhausting thought to have to navigate to the other side of my keyboard to close "This is Jeff". The effort of closing the window was not equal to the joy of opening that message. I'd suggest using E to close it as it's the same button to open it, or Space.
Controls really should be either shown on the main menu, or have prompts as you play. Hiding them in the pause menu isn't enough, I didn't know they were there until I went to quit the game because I couldn't find how to take a photo.
If your main menu is controlled with WASD and Enter, you need to capture and hide the mouse. I had to delete a comment from the Discord asking if anyone else couldn't get past the main menu. I decided to spam random keys to see what would happen which ended up starting the game after I hit Enter. As you can click on the option on the menu and get visual feedback, I assumed that it was the intended method to start the game and it did not work.
More of a bug, if you press E on one of the pillars, press space, then press enter, your character will jump when the window ends. Easy fix, just have a bool that determines when the character can jump and disable it when a window opens.
I believe you have met your personal goal of playing with the terrain tools to make something good, but I would be so much more enticed to see what you created if there were purpose for finding the lake, climbing the mountain. Look at The Witness for example. Fantastic map, and we explore it because the island is full of puzzles.
Overall, it's good for a walking simulator. You have walking, you have something to do, it just lacks that purpose. I like the audio selection, the asset packs, and the idea behind the game of the character finding inspiration. I didn't mean for this to be so negative, just wanted to share my thoughts. Hope this helps on your next submission!