Amazing concept and a great take on the theme:)
I was initially wandering around with no goal of what to do; however, I understood my goal when I got into the mouse maze. The two world felt interconnected and therefore interactive, giving a great experience. I can definitely see lots of expansions: maybe the real world will come with the challenges to retrieve keys found in the mouse world, maybe the two worlds could collide...
One small thing I want to point out is that there's not much of an indication to interact. It took me a bit to figure out what to do; Giving a text floating on the items and the inventory could help.
Great job!