My frame of reference is obviously WC3; imagine that, but with bridges being truly walkable and projectiles having real motion. As far as what I've already built goes, it is truly 3D even if the control scheme is based on a flat plane -- if you target an enemy above or below, your character's turret will pivot to shoot towards it. The basics, though, are pretty safely isometric and I'm just building up from there with what feels right.