for sandbox you have to spawn the rocks by pressing 1-8. 1 being the weakest rock, and 8 being the strongest rock. and for both sandbox and regular you have to use the mouse to drag the towers on ground that is not on the path, (the best is the one with the lightning bolt on it, the best upgrades are the "q" upgrades). prices are in the game.
All the credit goes to @redgreenandblue. full screen not recommended
