You can probably generate a random map using an outside program. I am not sure if it is possible to do it within Trem without rewriting the source, but I know little about map editing as of now. I made something in java using Prim's algorithm, I could rewrite that to output a .map file. I should note that I am pretty sure I could only get it working on a 2D map, that is one with no stairs, ramps, ect, or more technically all of the floors have the same z value.