It is still fairly novel for the main object of a game to be to stay on the screen. Considering there is nothing shooting at you either, playing such a game may seem a simple task...
Objectives
Scaffolding Sid is chased by a large black monster jumping from plank to plank to avoid it, while collecting points by dropping through blocks, picking up cherries and falling not too far. The more exercise this involves, the more energy Sid uses up.
In Play
The cassette comes attractively packaged with pseudo 1930s artwork. It loaded first time to display a title screen identifying the various objects in the game. The instructions proper are included in the cassette insert. There are four levels available for play and selection of one starts the game.
Pretty soon you realise that Plankwalk is not one of the super-detailed, multicoloured graphic works of art common nowadays. Sid consists of an inverted Y with a crossbar, the blocks are plain white squares and the monster appears to be a left-over space invader, although being drawn black on a dark blue background, it's pretty hard to tell. The cherries are multicoloured, but overall the graphic content is a little uninspired.
The game itself is a clever idea and works reasonably well. The various planks and objects scroll fairly smoothly up the screen, and you have to be quite nippy with the movement controls (left, right and fast) to avoid the pursuing monster.
Fall onto a white block and you pass through, gaining points, and drop onto whatever is below. Walking sideways through a cherry also scores points and your energy may be recharged by walking into an elevator. Some of the planks have a built-in slops or are false. These are indicated with different colours or flashing effects. You lose one of your three lives by dropping off the bottom of the screen, being lifted off the top by the rising planks, scurrying too far off either side or being caught by the monster.
The higher levels of play don't seem to have much effect on the speed or difficulty of the game, but provide more blocks, cherries and elevators, allowing you to achieve a high score with comparative ease.