Ocean were the first software house to develop games made up of completely unrelated levels. Batman and The Untouchables consisted of a series of levels featuring generic game types all tossed into one package. Whether this was to achieve maximum variety or the result of an incoherent narrative is up for debate. The levels were so different that separate programming teams were even used to code them. Nevertheless, their meteoric rise up the charts proved that it was a successful formula. Theme Park Mystery has been programmed by only one team, but each of the four levels is still a game in itself.

You've inherited the Magic Canyon Theme Park from your grandfather. The park is haunted by a ghostly presence that not only made your grandfather lose his marbles, but has also sent the entire staff and customers packing. Your job is to solve the mystery and make the park safe again.

Although categorised as an adventure, this is much more of an action game that requires thought to overcome the problems.

The four levels are split into Yesterday Land, Dragon Land, Dreamland and Future Land and you must visit each one in turn, solve the mystery, and pass onto the next.

Yesterday Land is the first to be tackled. Set in a railway station, it consists of three arcade games dating back to the 1900's. Before you can leave the station and proceed, you must collect a pass from Zoltan who is found in the first of the machines. You can't collect a pass without inserting a token into the slot. The question is, how do you find the token?

Theme Park comes with only very limited instructions because the objective of the game is to solve these puzzles for yourself. In this case, you go to the second arcade machine which has a series of tokens waiting in the reject slot. You can opt to play the machine or simply take the token back to Zoltar who, after some dramatic visual effects, offers you the pass. If you play the bagatelle machine, you can collect extra tokens which come in useful later.

Complete this problem and you take your pass to the station platform where a train comes to take you to Dragon Land. This is a horizontally-scrolling platform arcade section where you collect the fire and water demons and a casket. To proceed onto the next level you require the sleeping potion and though you don't need to have collected anything else to continue, you cannot complete the game without the extras. You spend a lot of time in this level avoiding a series of apes perniciously tossing balls. Once you find the sleeping potion you sink into a deep sleep and drift off to Dreamland.

In Dreamland the tokens collected in the first level become inportant because they're used to buy you sleep time. Without them your visit is so brief you might as well not have bothered.

This level is an animated adventure which takes place on a chessboard. The aim is to collect two demons. You need keys to succeed at this level and they can either be brought with you from Dragon Land or purchased by tossing gold coins to entice Origami birds to lay eggs and leave keys. As you scour the land, you come across the ticket to Future Land.

Reach Future Land and you're straight into a non-stop blast. This is an unashamedly trigger-happy shoot-'em-up section where you need to blast everything that moves while trying desperately to collect the floating balls and deposit them in the storage hold.

At any point in the game you can catch a train back to Yesterday Land and pick up a hint card from Zoltan. Since instructions are very limited, these provide cryptic clues to help in your quest. Zoltan can even hand out the occasional extra life, but you have to weigh up your need against the nuisance of replaying other levels.

There is enormous potential for exciting visuals in a game set inside a theme park, and to a large extent this game delivers. Special effects such as the gradual, magical appearance of Zoltar and the unusual and varied playing sprites in Dreamland are certainly a visual feast.

In other areas, the game is severely lacking. In Yesterday Land and Dragon Land, for example, the playing sprites are tiny and poorly animated. That's not to say they affect the gameplay to any great extent, but considering what might have been possible, it's a big let down that more hasn't been achieved. Using a technique known as palette switching, more than the standard 16 colours appear on screen at once, but the effect hasn't been used to any great advantage so the visuals don't exactly blind you with colour.

Any failings in the visual department are more than compensated for by the stirring soundtrack. The programmer of the game as also involved in creating music for the West German company, Steinberg. As a result he has put considerable effort into making sure the sound effects are atmospheric and impressive. The game opens with a long sampled intro tune and special effects appear profusely throughout the game. There's even a crack of electricity as Zoltan makes an appearance in Yesterday Land.

While early demos of the game showed off some promising visuals, it was always difficult to see just how the levels would slot together to form an addictive and exciting challenge. The long months of delay seem to have been worth it, because whereas Ocean's Batman and The Untouchables were disjointed, Theme Park Mystery is a very coherent and unusual challenge.

Nevertheless, the combination of adventure type problems with traditional arcade style levels seems strange. The average arcade freak is going to find the lack of help frustrating, while the adventure enthusiast may well be annoyed by having to tidy up his joystick technique. Its hybrid heritage could be the start of a whole new genre of action adventures or the kiss of death to a game that no-one feels at home with.