If you want to understand what Space Transfer is, you need to imagine the old electronic handheld game... combined with a freakin' Space Station. Tapping left or right side of the screen, moves the top and bottom bars simultaneously and prevents astronauts from becoming just another space debris. Transferring your crew from one side to another lets you earn points. Special astronauts on top of having their unique moves, let you earn gems (and points) when rescued.
Space Transfer Screenshots