How about a Boulder Tower, 1x1 that just blocks (5 gold).
Then the ability to stack towers up to three high.
If they are two or more high then other towers of lower height cannot shoot (or see) past them.
If they are three high then flying creeps have to go round them.
A 3D view could then be offered.
I would suggest to add and educational towers - closer to the reality of the world
Biologically dangerous Tower -
you get affected but it kills you over time
Ozon layer tover
as if it is stand under the ozon layer hole and also affect those who "get close"
Rubish Tower
rubish all around does not let you do what you want
What do you think?
Jamie
CD Duplicator
