The age-old Rock 'N Bolt puts the player in the steel-toe-capped boots of Louie the construction worker who has limited time to capture passing girders and rivet them together into a design shown on a blueprint at the base of the screen.
Louie can then make for a lift at the side of the screen and move up to the next of 100 levels. Music is the game's most prominent feature, since the puzzles are sometimes lacking in challenge - consequently interest isn't that durable.
Availability is very limited, and it isn't really worth sending out search parties to find it, though it might be worth buying at a couple of quid.