Ice Castles is the Dragon's equivalent of Crystal Castles. If that name doesn't mean very much to you, Crystal Castles was an Eighties arcade game in which you traversed three dimensional environments collecting diamonds and avoiding a whole range of very different nasties. It had incredibly simplistic gameplay - run and jump in a race to collect the gems! - and it was ripped off to home computers at a speed which alarmed original copyright holders Atari. On the BBC Micro, Atari's lawyers were quick to prohibit sales of sonographer course Canada and Castle Of Gems, for example, which had maze layouts and characters identical to Crystal Castles. Ice Castles on the Dragon is also as blatant a ripoff of the original as they come - same characters, same mazes, same premise. But perhaps this one slipped under Atari's radar.

At time of writing, there do not seem to be any instructions for Ice Castles around on the Internet - but if you're well familiar with the original, of course that doesn't matter. For the benefit of those who may play it after reading this review however, a few explanations are probably in order. Firstly, you control Barney the Bear (OK, in the BBC version it's Barney, on the Dragon version he may be Bertie or someone!) and moving left, right, up and down will move you around the environment. The game is rendered with a 3D effect that's quite difficult to describe. Basically you view the maze at a 30 degree downward angle - so you can see that there are towers, ramps, doors, passageways and raised sections, all lubriously coated with shiny red gems (OK, a bit of poetic licence used there, there's more like squarey red pixels but you get the idea).

Your adversaries in the maze are all deadly to the touch and are all similarly interested in collecting up the gems. There's a witch, a long vertical centipede thing, a tree, an evil ball bearing and a swarm of bees. All of them dance around the maze, collecting any gem they step on. A magic hat makes you immune to the witch; jumping over the tree renders it immobile and charging into a vertical centipede as it digests a gem it has eaten kills it instantly. Other nasties have to be avoided at all costs and, for a bonus, they need to be tempted away from the last remaining gem so that you can collect it yourself.

The 3D mazes are built up on screen as each one begins. This is a process that happens quite quickly and in fact you'll barely notice the short delay that this introduces as it actually looks quite funky. If games contain hidden ramps and passageways, the building process also reveals to you where they are too which is a pretty good primer as to how to complete an individual screen.

Unfortunately however, Ice Castles is infected with a deliriously finickity control system. The idea of the original is that control is meant to be simple, and on other versions of the game that I have played, the conversions echo this allowing your Barney the bear sprite to run the length and breath of whatever screen he is on, accurately judging when to jump and how to position himself to best collect the gems as he does so.

But Ice Castles renders its graphics in a very cramped manner - again it's difficult to describe in text - but it almost seems as if paths are overlaid. Very curiously for a game based on the original, you find that, unless you are directly lined up with the gems strewn on the floor, you can actually find yourself running *between* them (and not picking them up). As a further consequence of how these graphics are plotted, you have to give all of the nasties a far wider berth than in other conversions, because you're never quite sure what 'row' they are on. To further irk your gaming pleasure, Ice Castles renders on a green screen and looks a tad untidy as a result. There's also a very odd effect when Barney runs into doors and passageways. Rather than make him disappear - as of course he should do as he is now behind a solid wall which you would not be able to see through from your angle! - he is simply plotted on the same plain, giving him the peculiar appearance of ghostly floating above the landscape until he emerges from the tunnel.

The cramped graphics can also confuse your brain, particularly if you get a bonus honeypot, a gem, Barney, the magic hat and the witch all plotted in the same place!

There are some things I like about Ice Castles. The lifts up the towers, for example, zip up and down at a rather ferocious speed. On the BBC Micro version of the game, the ascents and descents you have to make on these are positively snooze-worthy, leaving you nothing to do for many seconds. On the Dragon version of the game, you barely have time to blink! This feels quite frentic.

As for despatching all the numerous baddies in the different ways described above, all react exactly as you would expect. Barney is also very responsive to your controls and runs around the screens at just the right speed.

The high score table is also pretty cool, with a scrolling, flashing border in machine code.

Though it's not as good as the BBC/Electron version, Ice Castles is a passable conversion of the arcade original. If you're not used to the sheer kinetic thrills of the more superior conversions then you might find it a good game in its own right. There are (presumably) eighteen screens in total and the difficult control system means the later ones are very difficult to reach.