Codex Gamicus

Harley's Humongous Adventure is a 2D platform game released in 1993 on the Super Nintendo Entertainment System where the player controls the miniaturized form of the title character as he navigates his home fighting off bugs using household items and negotiating other hazards whilst collecting parts of his shrink ray in order to return himself to normal size.

The story starts with Harley, the “hip young scientist with an IQ the size of Mt Rushmore” testing his latest invention - a shrinking machine - which explodes, somehow shrinking Harley to the size of a bug in the process. His goal from herein is to locate the scattered parts of the machine and reassemble it in order to return to his original height.

But this task is far from easy as now that Harley has shrunk, the place he once called home is now a treacherous wilderness filled with monstrous insects and vermin, including a rat which has a vendetta against him. To top it off things that were once useful appliances, work surfaces and tools are all death traps waiting to impale, burn, electrocute or drown Harley at a moments notice.

To progress through the game the player must guide Harley to the end of the level themed around a particular room in his house, e.g. kitchen, bedroom, attic, lab, by jumping across counter-tops, shelves, test tubes or whatever he left lying around, and avoiding cutlery, floating crockery, Bunsen burners etc. and the local infestation of bugs which he can kill using the stationary arsenal at his disposal.

After safely completing all the levels in a particular room, Harley must face off against his main recurring adversary, a giant (to Harley at his current size at least) deformed rodent. Who on each appearance is sporting a new artificial body part to replace the one Harley forcibly removed in the previous battle.

To aid the player in his mission a heads-up display (HUD) is provided on screen showing the players life bar represented by a line of hearts, his fuel meter which can be refilled by picking up the fuel power ups, a counter showing the number of nuts Harley has collected, remaining lives, and an icon displaying what weapon is currently selected and how many there are of it as well as the running total for the score which if good enough goes onto a leader board at the end. As well as the HUD the player has a variety of power ups to collect including: the aforementioned fuel power ups to power the jet pack, hearts to replenish Harley’s life meter, 1-Ups or extra lives which are shaped like a portrait of himself, the various weapons, and not forgetting the Parachute for those long drops that would leave Harley as just a stain on the tiled floor.

As the game doesn’t have any battery backup to save progress, to make it a little less sadistic, checkpoints (depicted as the kind of bells you find in hotel receptions), are dotted throughout the levels to provide a re-spawn point whenever the player “loses a Harley”.


Use the D-Pad to move Harley around, hold Y to run, B to Jump, tap A to throw projectiles, X to use the Jetpack and Select to cycle through the available weapons. Harley has other actions which are automatic and dependent on the environment including; suction pads for climbing certain surfaces, a parachute when dropping from great heights and swimming. Also, in certain levels, particularly in the toy room, Harley gets to command one of his toy tanks which can fire missiles to destroy any enemies/obstacles in its way.