@EpsiloN: Unfortunately I don't have Photoshop and there's no way I'm going to try downloading it on my connection, so that won't work. :\

Besides, I think I'll be ok without having slopes. It makes the game that much easier to program, since I don't have to deal with path finding between multiple floors. I'll keep the mountains and dips in my terrain, though, to provide obstacles for ground units. Of course I can also make air units that can move over these obstacles without problems.

On that same note, unit selection and ordering is working, so now I want to add path finding. I've played around with the scripts MrGuest referenced to me, but I noticed that both their speed and accuracy drops dramatically when there are a lot of nodes in a level.

So I was wondering, what do most game developers do to solve this problem? I'm guessing they precompute the various paths available to the AI before the game even starts, but how is that accomplished?