This is just out of the game box thinking. A while back a group of us were chatting about having a 3-D board in the real world where you would move actual carts, and have them drop into the board when chasms came out.
Could OTR be taken to the next level (downward)? The following combines elements of Iron Dragon and Robo Rally. You could add an entrance to a lower level, maybe at the side of the color blocks, maybe representing an elevator shaft, maybe a ramp. This is made up more then he game itself so you do not worry about ramps colliding with each other. You could have a more valuable gem located only down there and you would have a movement cost to go down, and a larger cost to go back up the ramp. Any chasm on the main board would crush anything underneath it. (ala one of the expansion boards for Robo Rally)
Could OTR be taken to the next level (downward)? The following combines elements of Iron Dragon and Robo Rally. You could add an entrance to a lower level, maybe at the side of the color blocks, maybe representing an elevator shaft, maybe a ramp. This is made up more then he game itself so you do not worry about ramps colliding with each other. You could have a more valuable gem located only down there and you would have a movement cost to go down, and a larger cost to go back up the ramp. Any chasm on the main board would crush anything underneath it. (ala one of the expansion boards for Robo Rally)