You have to hold down the buttons, then with the next mouse go up the stairs and so on, then theres a tripple button push in one room and 1 button on one of the first couple floors you have to hold down as well (total of 4) to get to the end!
"Munchkin: One who, on being told that this is a game about politics and intrigue in 17th century Italy, asks to play a ninja." — Andrew Rilstone