Thanks! I'm currently testing out making the map fully 3d and having proper heights. I currently have floor tiles that represent different heights (trenches for lower, water vs deep water, bushes/rubble that are half-height, and columns that are double-height walls), but the core data structure believes that the map is flat. I'm not sure what I would do to have that apply in 2D mode though. I would like to keep the game fully playable in both modes, but full 3d height will definitely complicate any projectiles that are traveling. Do fireballs track the floor height, etc.
And then there is still the list of interesting AI's that I haven't finished implementing.