Zaxxon is unique in the history of arcade and home computer games in as much as that, though regarded by us oldies as one of the original classics, it's never really been cloned.

The closest thing that springs to mind as far as gameplay goes is Uridium, but even that's viewed using a more traditional horizontal perspective. Zaxxon (for those of you too young to remember) appeared around the same time as Scramble and Defender, and was a strange mixture to say the least. Using the forced left-to-right scroll of Scramble, but over an isometric landscape, it introduced a new dimension to flying. And I mean that quite literally, because you could climb and dive...

This basically lead to lots of ducking and swooping as progressively more testing levels rolled towards the player, forcing them to fit through tiny gaps in walls, not to mention squeezing through breaks in force-fields.

Along the way various targets offer themselves up for destruction, including fuel dumps, missile silos, and numerous ground targets such as enemy aircraft and towers. An altimeter at the side of the screen shows exactly how, er... high you're flying (No? Really? - Harry) while the craft itself shrinks and grows giving a more immediately visual clue as to where you are in relation to other objects.

After each landscape, the traditional end of level guardian trundles on, with the normal "hit 16 times to kill" rules applying. After this you travel through some open space against a few waves of enemy craft (who dive and change height rather annoyingly) and then it's back for more of the same.

As you've probably guessed, I'm not just recounting this for my own entertainment, but as instruction for what is essentially a spot-on clone. It's probably not the sort of thing that'll stand up too well in comparison with many of the other arcade games on offer in the PD sector, but for the nostalgic, goes down very nicely with a can of Vimto and a Human League album. (I'm just off to wipe a tear from my aged eye!)