LOGOTRON was reknowned for little in the gaming field except for Xor, a strategic 2D maze game. Suddenly, after the excellent Star Ray, the company has hit the Amiga scene with a bang. The next release is Quadralien, a sci-fi puzzle game with shooting, back in the Xor tradition.

As well as a reactor heading for meltdown the luckless player has to contend with an invasion of aliens, a rogue computer, and a whole host of fiendish puzzles. The reactor, known as Astra, has three levels comprised of six chambers and the reactor core.

The complex part of this game comes in the form of slave droids which either repel or attract, just like magnets, and supposedly control the plant's day-to-day maintenance. The whole thing is rather confusingly referred to as the Dynamic Magnetics System of Entropy Control, or DyMSEC.

The primary aim is to avoid a meltdown by preventing the core temperature from getting too high, or the operations energy from sinking too low. Plus finding and destroying the Quadralien Mother.

To reduce the plant's temperature you must manoeuvre one of your droids so that it sends water barrels down chutes, or reduce the entropy level which is a measure of the movement of the DyMSEC. Tortuous or what? You control two from an initial selection of six droids as they run around the various mazes, shooting obstructing objects and absorbing others.

Each droid has its own special characteristics, from using a headlight to illuminate a darkened chamber to brute strength when shoving objects out of the way. The correct choice of droid depends on which environment you are confronted with.

What makes the game interesting, or stupefyingly dull depending on your point of view, is the way the various objects on screen interact with each other. So in order to create a certain effect or reach a certain place it is first necessary to work out where everything is going to end up.

There are loads of different types of objects, plenty of options for making the game more playable, such as code words to bypass the lower levels once completed, and a number of ways in which it can be tackled.

David Whittaker's music is pleasant enough, but the crude flip screen scrolling is irritating, and although the graphics are serviceable, Quadralien isn't pushing frontiers back in any department. I found it all a little tiresome.

Quadralien, Logotron's second release after Star Ray bears a slight similarity to other games in the ageing Gauntlet genre, insofar as it's a multi directional scrolling affair viewed from above. In true corny plot fashion, Quadralien is set in the distant future and takes place on a huge computer controlled energy base in deep space by the name of Astra.

For some unknown reason, the computer that run the base have shut down and subsequently the base is dangerously close to meltdown. Your mission is to stop the reactor from melting down and destroy the mother alien in the central reactor.

Fortunately, you don't have to travel to the base yourself. Instead you're given two droids (from a possible choice of six) to do your bidding by remote control. Each droid has its own specific strengths and weaknesses, and learning exactly what they are is part of the key to success.

As part of the computer malfunction, all the levels of Astra apart from level one have been sealed, and progression to the higher levels is achieved by reaching a certain score, whereupon you are allowed access to the next one.

If you can't be bothered to go about solving the puzzle in the game, you can simply blast everything you see with your lasers until the target score is reached. This however is a time and energy consuming process, so the best way to actually complete the game is to set about actually sorting out the problems on each level in turn.

The puzzles are of a fairly simple nature and require more dexterity than strategic thought, due to the game's arcade overtones. For example temporarily slowing down the bases rapidly rising temperature is done simply by nudging up against a barrel of cooling fluid and pushing it down a chute.

Completing the mission is not just a case of methodically dropping barrels down holes and blowing up doors though. There are Quadralien nasties lurking about which pose problems all of their own, while there are certain parts of the floor that must be avoided, such as the earthing boxes that immediately drain a droid of all its power should it stumble onto one.

Fortunately there are places where hapless droids can take a sort of pit-stop in order to refresh themselves. The information consoles allow you to recharge your batteries, clean any radioactivity from you and gain information on the current level's features.

Quadralien is a bit of a letdown after such an impressive debut release. It seems to me that the designers have tried to produce something completely original, and they deserve credit for that alone. However, the game has been very poorly executed, and the end result is something of a disappointment.

Badly defined sprites and backdrops accompanied by extremely shaky scrolling all helped to put me off from the very start, as did the terribly depressing music (probably David Whittaker's worst so far).

Gameplay suffers quite seriously as a result of these cosmetic shortcomings, and because of this the overall product falls uncomfortably between mediocre and dire. Give it a miss.

In the mid twenty-first century, the strange Quadralien forces begin to appear in increasingly high numbers. Until recently they have been rather annoying, but no more. Robbing ships and stealing supplies was all their activity added up to; but now they are acting much more menacingly, threatening to invade the colony worlds of our solar system. They have already killed humans without robbing the craft, an act which suggests that something is afoot...

You are a travelling technical engineer, specialising in dangerous situations involving nuclear power and other radioactive power sources, and are not to pleased to be dragged out of bed to rush to Jupiter's Astra station. When you hear the reason for you hasty summons, your agitation is replaced by increasing apprehension.

It appears that for some reason DyMSEC (Dynamic Systems of Entropy Control) has gone haywire, shutting off the central computer's external communications circuits and ignoring the riding reactor temperature. But that's not the only problem...

Astra's main purpose was to transmit energy along quantum-quantum beams to long distance stations and installations. However, it seems that the Quadraliens have found a way to travel along these beams and have infiltrated Astra station.

So your task is twofold; search the ship, dropping collant barrels into reactor shoots and reducing the entropy to keep the core temperature down, and find and destroy the mother Quadralien - otherwise, their forces could extend throughout our solar system, leaving a trail of devastation wherever they go.

The central computer has locked out all the higher levels, so you must clean the lower levels to reveal an access code which will enable you to use the lift in the uppermost levels of the reactor station.

However, due to high levels of radiation in the plant after malfunction, you can't personally enter the rooms. Even a strong radiation suit won't protect you. You must send in six remote drones to carry out the tasks required. These range from a standard 'tug' type drone to laser armed drones.

You must succeed in securing the station. The aliens have already tapped into Jupiter station's power beam. Who knows where they could infiltrate ne click, bzzzzzzz...