Lode Runner is based on the old Broderbund Software computer game of the same name, and was in fact designed by a Broderbund employee.
The game contains eight different game boards of varying difficulty level - one of these is used for 2-4 players and two or three are recommended for 5-6 players. Each player controls a runner and a guard and presumably tries to have their runner collect as much gold as possible while eluding the other players' guards.
[More detail will be added to this description when a better rules summary or translation is obtained.]