Click to scroll through maze boundaries. there are 5. Space to generate/reset maze Arrow keys to move You can't change maze boundary while the maze is active, so if you want to make a new maze with a new boundary you will have to either finish the maze or press the green flag. If you want to make the maze bigger or smaller, uhhhh... press see inside and change tile size. The Boundaries may get a little weird but its fine.
Thanks to griffpatch maze generation tutorial. Griffpatch my goat. https://scratch.mit.edu/users/griffpatch/