The first hidden movement game we've enjoyed.
Many years ago, there was a game on the Xbox that I used to play online, spies vs mercs, from Splinter Cell : Pandora tomorrow. A two vs two game of trying to sneak in and do stuff while being hunted. This game, brings back all the fun I had back then.
Being 2 vs 2, it's easy to teach, as you can have a pair of more experienced players each teaching a newcomer how to play. And once both teams get up to speed, there's quite a bit of clever puzzling to do.
There's enough information to have a good idea what they might be up to, but enough ways they could change things that you have to make guesses.
Definitely a interesting puzzle and an original design for a box, acting as the shield and scoreboard.