This script uses either depth-first search or Prim’s algorithm to generate complex mazes either in the editor or at run-time. It can also scatter obstacles or enemies throughout the maze. Its clean interface and flexibility allows you to use complex artwork and avoid a blocky look. You can generate mazes from scratch or define certain paths your maze must follow and let Maze Creator fill in the rest.
Check it out at the Unity Asset Store.
You can also download the demo for Windows.