Nobody is quite sure what the powers of Zythum are. It is known that it is a magical drink that lies hidden somewhere within a castle which is, in turn, situated somewhere amongst some of the most inhospitable countryside in the land. It is also protected by assorted custodians who will do their utmost to stop you from gaining access to it.
There are four different zones to be crossed in turn and you only have eight minutes of real time to complete each zone. Crossing a zone involves leaping over various pits and shooting or dodging the custodians. There are two ways of shooting them - a single blast from your limitless supply of energy bolts or by using one of your precious light bombs which removes all the custodians currently on screen. Contact with a custodian costs a life and moves you back on the map (shown at the bottom of the screen). Likewise if you run out of time.
The holes are of differing sizes and you must judge your leap accordingly. How far you jump depends on how long you keep the fire button depressed. Along the route are various items that you can collect. These can offer you temporary levitation, immunity or invisibility or can add bonus points or replenish your supply of light bombs.
The game's graphics are no more than average but the biggest let down is the lack of variety within Zythum. You must always pursue the same route and meet the zones in the same order and this rapidly reduces any lasting interest in this game.