Yep, you can view the map from 4 different angles. You can see the map rotation being used in some of the development videos.
And, yes, it’s a lot more work making an isometric engine than a top-down engine. With an isometric engine, because you have a pseudo 3D environment, all the sprites have to be drawn in a very specific order, or objects that are supposed to be behind other objects will clip through them. One of the things I’m working on with elevator is making sure they don’t clip through walls when I start moving them up or down. The elevator sprite currently consists of 11 subsprites that are drawn in a specific order, and when the elevator is moving between floors, a lot of these sprites will have to be drawn twice: The bottom part of the sprite is drawn when drawing the lower floor (i.e. the floor the elevator is moving from when moving up), and the top part when drawing the upper floor (the floor the elevator is currently moving up to).