Currently it uses forest as the tileset and megapack as the techtree, though the techtree really doesn't apply in this case.
I think it should ask for the tileset, as tilesets CAN change the map. For example, Anex had some larger than normal objects that were made to ONLY work with a specially made tileset, and would look terrible in a regular tileset. As well, maps can look very much different in different tilesets, and a map intended only for the desert tileset might look rather odd in a forest tileset.
There was some bugs in how GAE tried to do it, and I don't know if they fixed it yet, but their map editor had a preview option that opened a dialogue box to choose the tileset, presumably to pass both the map and tileset to the game.
As well, there should be some support for the map not being in the maps folder; such as someone testing a map by quickly saving to the desktop (etc). Feeding an absolute link to the engine when the map isn't in the maps folder would presumably fix that.
