They will LOVE it! I just got back from WDW and spent one evening at Disney Quest (or "Disney in a Box"). It is five floors of various games, all free to play (of course, entrance to DQ costs some $30-$35; we had an Ultimate Park Hopper, which includes admission to DQ). All sorts of video games and virtual reality games. One of our favorites is called (I think) Cyber-Roller
Coaster. You actually design your own roller coaster ride on a computer; you then enter your own personal "coaster", are strapped in, and away you go! The coaster is a pod that (while staying in one place) flips about, somersaults, etc, according to your design: you sit facing a screen that projects the track ahead of you.
DQ is a popular place, especially at night when a lot of local kids come out. However, I imagine that March would not be too bad. Two years ago we went on a Friday night in late February and had no crowds at all.