Hmm -- what kind of unit, and what kind of building? (Horseman can't garrison, and only workers can garrison Laboratories). If you're trying [G]+click with a foot soldier on a healthy-enough tower, I may have some investigating to do. =P
Green Beret, can't remember the makers. You can play it on MACmame, a downloadable program that lets you play stuff like this on demand. So long as you download the game you want to play as well.
This game needs to be much longer then it is now. a few more levels, a skirmish mode, heck lets ask for a level editor while we're at it. This game is just so brilliant!
My only complaint is that after a certain level of wisdom the skeletons summoned by the 'Necromancer' class don't get any stronger. this is a big problem on later levels.
In the Instructions, it says to use 'Shift' instead of the mouse if you can't get the mouse to work.