Nice work on procedural generation of the mazes. Since I haven't tried anything procedural yet, I'm wondering if you had to include some kind of 'max walking distance' parameter to ensure that the traversal distance generated was do-able within the 60 sec timer.
I completed three tries and in had between 8 and 4 seconds to spare. In all cases the mazes were pretty straight forward and I didn't need to do any back-tracking. So it felt like the total distance walked through the maze (more than just corner to corner) was somehow nicely baked in.