I have a lot of memories making mazes in Rollercoaster Tycoon so this game really scratches that itch. It's pretty fun for a casual game. You've gotten the country fair vibes spot on. Add more scenery and it would be even more fun to play with in the editor.
Most of my suggestions are probably things you are thinking of already or are going to get around to it sometime soon, such as an options menu. I do like the quake FOV, although an FOV adjustment option might be a good idea. Another suggestion might be to prevent saving if the maze itself is impossible.
Anyway, those are my ideas for now. As a casual game idea it's simple and perfect, and I don't know if you should deviate much from that maze focus.