The game has a good idea, but it wasn’t executed to the best level.
The game lacks lighting, texture variety and there are issues with the part alignment.
I recommend improving the lighting, and adding different textures to everything, to make the place a bit more lively. When I played, I could see that parts were misaligned, and I knew that it could be better.
If you need help for aligning, you should get a plugin or something else to snap to the other parts.
The GUI might also have some problems, but I don’t know if that is a personal choice or just a bug.
Aside from all that, good work.
All of the walls have SmoothPlastic, and that could be severely improved by using materials like Concrete and etc. If you want to go one step further, you can use textures (a.k.a decals ((e.g brick and stuff))) to spice up the game a bit.