What would happen if you went round some of the C64's top programmers and asked for a budget game each? The programs might be games that didn't quite make the grade for full-price release, superslick conversions of Spectrum budget games, or fun projects programmed in their spare time. In effect, Hewson asked the question of Graftgold (Paradroid), Sensible Software (Wizball), Apex Computer Productions (Retrograde) and a relative unknown - Martin Sneap (Knucklebusters).

4th Dimension is the result, and it could well be the most fun package we've ever seen. The quality of presentation is universally excellent and playability is amazing. A dash of originality and a few more levels could turn any of the games into a worthy full price release. As it is, they're available for a price which works out as only 24p more than most budget games.

To save confusion, we've reviewed each of the games individually. These marks are worked out in the same manner as budget ones, obviously a little more generously than would be the case for £10 games.

What happens when a droid breaks one of Isaac Asimov's famous Robotic Laws? Well, of course it goes to prison. And in the future, prison overcrowding has got so bad the prisons have been put into orbit around three planets. The robots are smart though, and escape to the planets below via transporters. Unfortunately, the Star Trek-like technology accidentally activates the droids' self-destruct mechanisms.

The Cyberdyne Warrior is despatched to return the droids to prisons as all the planets are inhabited by lots of extremely hostile aliens.

Each of the three planets are represented by large, multi-directionally scrolling caverns. There's a big range of aliens, with skulls to blind you and plenty of loose change to pick up. Once you have found one of the droids, you can go to the transporter and beam-up into a shop. Here you can improve you gun's calibre and shot speed, or buy extra ammo, time and energy.

John and Steve Rowlands were Apex Computer Productions when they did this, but have since mutated into Transmission 'Retrograde' Software. Cyberdyne has a strong resemblance to Retrogrades duct section, but is much, much bigger.

The size of the planets mean you've got to do plenty of exploration and there's also a strong tactical element in judging when to return to the shop and which upgrades to buy.

The graphics are quite excellent, completely different for each level, while sound is fine with enjoyable spot FX. Although gameplay is unoriginal and not a massive challenge, playability and presentation are quite excellent.

What a brilliantly presented game. From the opening music and title sequence to the great in-game aliens and neat animation of the hero. Cyberdene Warrior is a pleasure to watch and play.

The platform action may be simple but it's extremely addictive and a severe test of arcade skills. In fact, in some ways it's even more enjoyable than Retrograde as the money is just lying around so you don't have to spend ages shooting aliens to collect it.

While the basic leaping-'n-shooting gameplay is very familiar, Apex has worked a spell of amnesia on us cynics with some superb graphics and gameplay. Once you find the droids, it becomes both infuriating and immensely addictive as you try to recover them. But it's worth it - level two's jungle is superb, with bats, bubbling lava, and palm trees! Great blast-'em stuff which tests both joystick precision and tactical thinking.

The plot of a thousand Sci-Fi movies has come true: earth has been invaded by insects from outer space. The only humans left alive are some babies in the Rhineland, watched over by Saint Helen, a busty beauty with laser-firing eyes!

Helen has to stop bees from grabbing babies and dropping them to earth with a splat. If all the insects are killed, a bonus is given for the number of babies still alive. Innovatively, there are two planet surfaces, at the top and bottom of the horizontally scrolling play area - babies from the top fall upwards!

Another extra is the dust cloud which can be conjured up at any time and, when entered (with fire pressed) warp Helen to the nearest nicked nipper. Helen's a big girl, so she can carry more than one baby at a time. By entering a dust cloud (without fire pressed) the babies are stored in hyperspace until the end of the level, and Helen gets an Extra Bonus Feature - such as an extra smart bomb, shield, a laser-firing cherub escort, or even skips a couple of levels.

Helen certainly needs all the help she can get, because besides the baby-napping bees there are bullet-firing flies, mine-laying butterflies, super-speedy smiley-faces, and Devil's Eggs which explode into lots of little hming maggot worms.

At last a game which takes the Dropzone format, throws in a air few new features and equals, perhaps even betters that old favourite. On the debit side the graphics, while techncally superior to Dropzone, don't gel together quite as well.

But on the other hand, gameplay is much tougher and gets harder with each level. The variety of villains is good and they quickly mass up into fearsome formations.

An excellent variation on the Star Gate theme and truly an instant classic.

Insects In Space is a neat and very playable Defender variant. Attractive graphics add a lot to the simple appeal with some great insects and the erm... topless Helen - she looks like she's being stung by a couple of extra large bees!

But, although derivative, this isn't just Defender with different graphics. The dust cloud is a good idea although often as dangerous as it's useful, while the dual planet surfaces add something new too. Add a dose of sick humour and some over-the-top arcade sound FX, and you get instant (in)sects appeal. This is my personal favourite of the four games.

Yeah!! A good, solid, 'brain off, fire button at the ready' blast!! The gameplay is Stargate to a tee which should see legions of Dropzone/Guardian fans drooling to play.

The graphics have bags of detail and masses of colour, not to mention a risque main sprite to liven things up. Flies buzzing in chorus (a la 'The Fly') being the intro tune, while in-game FX are superb.

An evergreen classic!

Six helpless baby bubbles have been kidnapped, each one hidden inside a maze of fiendish complexity. To help you, or perhaps more honestly confuse you, there's plenty of teleports (sparkling clouds of magic) to zap you from place to place. But merely finding the baby bubble isn't good enough: you need all eight pieces of a scroll to free them from their magical paralysis. The pieces of scroll must be collected in the correct order, and once you've freed the baby you must take him back to where you started the maze.

Needless to say, there's plenty of baddies out to stop you. Storm clouds with flashing lightning and fanged baddie bubbles all take a life on contact. They can be killed by blowing bubbles at them, and if you pick up a magic toadstool your bubble power is increased!

I'm not usually one for maze games, but Mission Impossibubble is so addictive, I was totally hooked.

The 'search and find' gameplay is very easy to get into but surprisingly tough - I couldn't even get past the second level. Fine isometric graphics and good FX help to make Mission a minor classic.

Question: Why on earth did Hewson release Mazemania on full price when they had this gem lined up for budget? Impossibubble is a million times better, if not more. The graphics are great, really showing off the C64's scrolling and full colour sprites. The lightning flashes of the baddie clouds and the crystal bullets are delightful.

What's more, the graphics change: level two is clearly inspired by Bounder, while level three is the spooky one, complete with ghastly rotating eyeballs and skulls.

Gameplay is similarly top class. I usually hate maze-games but this one has such a strong arcade element I was addicted. Every game seems to reveal that much more of the latest maze, while the fast-moving baddies mean you can never take any of the levels for granted.

Insects In Space may be the best in the pack but Mission Impossibubble isn't far behind. There may be only six levels but they're all quite different. Graphics such as rotating tennis balls and spinning eyeballs are brilliant.

The unpredictable appearance of these baddies break up the basic maze game, making it a tough shoot-'em-up as well. Superb!

Weird one this, about a decapitated head (called Head, funnily enough) who bounces around in search of his girlfriend who's been kidnapped by the Globoid Hells Angels.

Before Head reaches his beloved, however, he must collect enough gems to trade with the Globoids for his sweethead. Contact with any of the Globoids along the way means instant loss of life. So it's just as well Head's 'armed' with ten shots, a shield, and two smart bombs.

If he gets to the end of the horizontally-scrolling level within the time limit, Head is transported to the next. Jumping into the special portals on some levels puts Head at the controls of a spaceship in a simple shoot-'em-up. The reward for killing all the attack waves is extra weapons.

Aaargh! This is maddening! Mistakes are so easy to make and often send you back quite a bit. What's worse, dying doesn't restore any of your weapons! But at least the sub-game is a satisfying blast which compensates for all the frustrations of the main game.

Although a very simple game, graphics and FX are all quite attractive while gameplay is very addictive. Not perhaps as instantly playable as the other games, but a good challenge.

Simple game concept, very difficult to beat. To my mind, the sprites make the game very jolly and changing with each level. It's a pity pinpoint accuracy is required though!

I love the idea of collecting diamonds en route to the final confrontation wth Gobba and hoping that you've got enough to buy back your girlfriend. Pure sadism!

Although disappointed by the fact that it isn't a footie game, I found Head fairly playable. The graphics are a bit Spectrumesque and the whole game seems old-fashioned.

Initially, you even wonder why Graftgold bothered converting it. However, once you start playing, simple but tough gameplay quickly elicits a desire to see the next level, and Head turns out to be surprisingly addictive; definitely a wolf in sheep's clothing.

Cyberdyne Warrior 90%
A surprisingly addictive blast-'em-up cum platforms-and-ladders game.

Insects In Space 94%
Killing insects has never been so much fun!

Mission Impossibubble 90%
Pure entertainment!

Head The Ball 84%
The weakest game on the compilation - but still very playable!