Topologika's second slot this month concerns a troubled and divided kingdom. As the rightful heir to the throne of Hamil, you were kidnapped in early infancy. As you grow older you are able to devise plans for escape and, following a long and exhausting journey, finally reach the shelter of a primitive chapel within the confines of your disinherited land. It's not long before you fall into a deep and dreamless sleep.

As you awake you realise that the chapel is surrounded by enemies on all sides; to leave it would mean almost certain death. You notice a metal rod, a piece of slightly whiffy steak and a bicycle lamp. Perhaps there is more than one way of getting out of the chapel...

The kingdom of Hamil turns out to be far from ordinary. In addition to the inevitable castle, it hides gigantic fountains, a bizarre museum and a complex system of underground caves. Exotic prehistoric time pockets are situated only a few steps away from treacherous mazes concealing untold treasures. Avoid sudden deadly rockfalls, try not to get cut off in a dead end and the crown jewels of Hamil may come within your legitimate grasp.

Location descriptions are suitably atmospheric and often extensive. Success depends on careful mapping and re-mapping of the environment; of many possible routes only one or two will lead you to safety. Being buried alive in a chamber of the maze of Hamil or failing to negotiate prehistoric paths only to plunge to your death to become a tasty pterodactyl snack are occupational hazards. Ingenious variations on the labyrinth theme are designed to delight and frustrate. Maze lovers will spend hours mapping, saving to disk, checking and rechecking; lesser dedicatces might just take a peek at the inbuilt hint system, clues from which come in graduated form ranging from cryptic hints to full-blown solution.

As the future king of Hamil, you find a host of hostile and dangerous subjects. Pause for too long in one place and a huge rat, crow, aardvark or hat sweeps in to gobble you up: This lays obvious difficulties in the way of making a map but is also one of the easier hazards to avoid. As long as you keep moving you're unlikely to end up on the menu of a gigantic mutants' feast. A tyrannosaurus trampling towards you, a blood-thirsty vampire, a vindictive hobgoblin and a sobbing hexapod require a little more care. In some cases escape is the best (and only viable) policy; in others a little devious dealing might be of more help.

Sudden death is obviously a constant hazard. RAMSAVE would have been a useful facility but on disk it's not that sorely missed.

Jonathan Partington teaches Mathematics in a Cambridge college and insists that his adventures have an inner logic of their own which isn't always immediately obvious to the player. Kingdom of Hamil certainly creates a very bizarre, unpredictable atmosphere which makes its problems all the more challenging to solve. Topologika rates the difficulty level as medium. Although at first the puzzles might seem more baffling than that, they become more manageable once you've mastered the adventure's slightly idiosyncratic tone.

The parser is of standard Topologika complexity with the usual acceptance of commands connected by AND or including ALL and EXCEPT. This is my third Topologika adventure and I still haven t got used to the absence of the EXAMINE command. A program that only responds with don't understand' when you attempt to look at an object more closely gives a constant reminder of its own limitations. All the potential for encoding clues in object descriptions is lost and there is no scope for further development of the atmosphere. In an adventure filled with bizarre creatures and even wilder landscapes, extra detail could only have been a bonus.

A maze-based adventure with a difference, Kingdom Of Hamil is bound to appeal to avid mapmakers. Others will be attracted by the off-beat scenario, the combination of prehistoric and magical elements as well as the promise of an array of weird and wonderful Hamiltonian beings. Available from the same address as Acheron, Kingdom Of Hamil retails at £9.95.