H-Mode7

[JayRay]

But what you CAN do in H-Mode 7 is create the foliage of the trees as Event Graphics (a charset of nothing but tree foliage) build your "Trunk" out of tiles, and then add the event graphics in tthose spaces at different angles for a tree. I believe you can even move event locations to flesh that out. It's not Minecraft, but it'll work in a pinch. Alternatively, Paper cutouts of 3d rendered "tree graphics that change depending on the angle, can still give that same feeling of 3d by using a billboard system.

This is usually only good for basic things like Trees and Signposts, stuff like this that can't be displayed correctly. For buildings and terain, you might want to stick with the tiles.