I don't get it.

The three oldest children are completely and totally fascinated by my husband's computer game. I just do not get it. It's an old DOS game, so the graphics are almost not recognizable as what they're supposed to be, the action is akin to a board game and the sounds effects are pretty pathetic. But all of them will sit there and watch for as long as he plays. Maybe I should just be grateful they're all occupied and nobody's making a mess?