You can create a maze with simple numbers:
1 = left,
2 = top,
4 = right,
8 = bottom,

If you want to create a full closed tile its: 1+2+4+8 = 15
Bottom and Left Corner is 1 + 8 = 9 = 09

Openscad needs a simple to parse string, so you had to write numbers with 2 digets ("09"). A new line is startet with "br" for break. Every Line had to be in the same length! Be sure to end your string with a br!

a simple box is: mazestring="03,06,br,09,12,br";

Every Tile has its own walls.so if you make a [4,1] there is one big wall with double wall thickness between the tiles. with [0,1] you make a wall with normal wallthickness.
(You can see the effect in my testmaze in the top left corner. The straight wall at second Position to the bottom has a little edge in the middle. this is because i switched between a richt wall in first osition to left wall in second position)

Inspired by
http://www.thingiverse.com/thing:24604
But not a real derivate.

Imagine a maze
Write the maze in the digit code
print
play

IMPORTANT!
Be sure that every line has the same amount of elements!
Be sure that your last line ends on "br"!