I've been doing a bit of thinking about Subway Shuffle.
I took the prototype you gave me and the river crossing board and came up with the following.
Below is some game piece tokens that happened to fit into the River Crossing holes. The base of these tokens is about the same size as the holes, so they make a nice fit.
So I mutilated my card a little to make it work with the RC board. Here is the result:
This worked fine. A pleasing feel. Since the pieces are not jumping from peg to peg (like hoppers or leaping lizards) but are moving and then inserting from hole to hole, the movement is acceptable. I would describe this movement as a spaceship moving from station to station. And if the story was about space ships moving, then this slight inserting movement could be described as the space ship coming down and landing at that space station. And if the token moves over more than one station (like the red one in the challenge above), the space ship could simply be described as flying over the middle station and then landing (that slight inserting motion) at its final station destination.
One other note, the prototype cards fail in the following sense. The stations(holes) that are not part of the challenge are still punched in the card. I believe one of the real benefits of using the River Crossing model is the fact that all the holes/stations that aren't involved in the challenge are not a part of the card. So there is no mistaken movement of using a station that is not a part of that particular challenge. I really like this about the card/river crossing system.
Another benefit of using a space theme, is that there would be no explanation needed for a child to believe as to why the red space ship can only move along the red flight path. Other themes I contemplated like different types of bikes, the story had to justify why the dirt bike could only move along the dirt path but not the path the road bike might be designated to.
I also like that if the final destination was earth. The sense of bringing your space ship home.
And of course the point that you brought up Bill, that if these were "circular" space ships or flying saucers, than pointing in the right direction to move would not be an issue.
So there you have my thoughts and work on "Space Shuttle"! :)
Tanya