I remembered coming across an interactive bouldering game a while ago, which used a projector to light up holds to create a custom problem each time. I couldn't find it with a quick search, but I did find this list of bouldering wall games:

http://www.canadarockclimbing.com/games.html

which includes 'Pointer', where a partner uses a broomstick to point out the next hold in the sequence just as the climber has reached the previous hold.