ADRENALIN knits the chubby forehead into a furrow of concentration as the child edges down a grey corridor. Lips tightly pursed, temple throbbing, a short forefinger strokes the trigger as he prepares to unleash a hail of bullets at any movement in the gloom ahead.
The protruding metal muzzle swings back and forth menacingly - daring anyone lurking in the shadows. The machine-gun bursts into life and its fiery outpouring is cleaner than the shrill grinding of the chainsaw, a weapon which sprays blood thickly enough to obscure his vision.
In computer-literate Hong Kong, children sit transfixed before a flickering screen for up to six hours at a time, their ears echoing with shrieks, screams and gunfire and their minds absorbed in the task at hand - kill or be killed.
The game is called Doom and it is hailed by terminal 'Terminators' as the ultimate keyboard thrill, but decried by psychiatrists and software critics as one of the screen's most violent and dangerous role-playing games.
'It is a very dangerous concept for children: if they want to win, they have to kill their opponents,' Hong Kong Computer Club director Peter Leung Ching-boon said.
'If they take it into real life, they could hurt their classmates.' Doom is a game developed by a Texas software company and networked throughout the world. One version - an extensive 'taster' - can be downloaded from the global Internet system but game addicts must pay for the full, three-times-larger version of the game.
KPS video and computer games stores have already sold about 200 copies of Doom , half of which included a game manual translated into Chinese, but illegal copying is estimated to have spawned hundreds more. It flickers to life on an unknown number of Hong Kong computer screens, introducing itself as Doom, a hellish 3-D game by id Software.' Computer experts acknowledge children and teenagers are a major market for on-screen role-playing games; youngsters devour each new game which arrives in the territory. They need not fork out big bucks for the real thing - illegal copies can cost less than a couple of Big Mac meals. Doom offers to swallow its player into one of three netherworlds: Knee Deep In The Dead, The Shores Of Hell or Inferno. Through dedicated keyboard tapping, the player can scale a ladder of four skill levels: I'm Too Young To Die, Hey, Not Too Rough, Hurt Me Plenty and Ultra-Violence. This week, Doom 's Texan manufacturers faxed Hong Kong users to advise them of a new, tougher skills level called Nightmare, soon to be in place.
Players already have a range of weapons at their disposal, including a pistol, a shotgun, a Gatling gun, an electro-plasma gun and a rocket launcher. The chainsaw - shades of the Texas Chainsaw Massacre - 'comes up intermittently' along with 'buckets of blood,' according to one Hong Kong player.
In a Doom scenario, the computer screen creates the impression of gazing through the eyes of a gunman - or chainsaw handler - as he stalks the corridors and rooms of each 'episode'. A running tally set into the bottom of the screen keeps track of the player's steadily climbing kill rate and a computer-generated face streams with blood as the player's 'health' declines.
Its graphic and non-stop violence has given the game cult status, outdistancing the controversial Mortal Combat in gore. Its Texan developers promise players will be able to battle, not just the computer, but other keyboard operators through computer links.
KPS assistant purchaser Lo Wai-hung said a new, more advanced version called Doom II was already hot property in the territory.
'I know it's available in Hong Kong, but KPS doesn't stock it. I think they're copies,' Mr Lo said.
Mr Leung runs a computer education programme for Hong Kong primary and secondary school students. His staff spend 30 hours with each class group, teaching them the essence of programming and computer theory. But many students are already adept with their keyboards after spending hours fitting and playing the latest computer combat games.
'They spend a few dollars in Shamshuipo and get a copy. Once one student gets a copy, the whole class will get it,' he said.
'According to some parents the children play games at home for hours, longer than they watch television. Children are interested in most computer games because they have direct interaction with them. Their playing response is much quicker than adults.
'In Hong Kong most parents work and they come home late. They have no control over their children and the computer.
'With the fast development of software, computers now have big memories and the photoscans can put sex pictures into the computers. Two or three years ago you could only put the outline of a picture on the computer, but now you can transfer the whole picture.' HONG Kong Computer Society president Yung Kai-tai said the lack of government knowledge and categorisation of computer games was a dangerous loophole.
'When you're using a computer game you could sit in front of the terminal for hours. With a video, you would only sit in front of it for a couple of hours. You wouldn't want to watch the same video seven days a week,' Mr Yung said.
'I consider it more dangerous than videos or magazines. If someone has interesting software the message can spread very quickly.' But zapping the offensive computer games or classifying grades of software is a difficult business.
'It's very difficult for TELA (the Television and Entertainment Licensing Authority) to acquire the level of skill to determine whether something is very violent,' Mr Yung said.
'It's not like a video, where you just play it. In a computer game it's stage by stage. You may have to play up to stage 10 before it gets really violent and unsuitable for children, so you must be a really good player before you can prove it's not suitable. Who's going to do that?' Psychiatrist and Federation of Youth Groups member Dr Peter Tsoi Ting-kwok said many parents were oblivious to the long-term effects of children sitting hunched over their computer terminals for hours.
'Violence can be learned - that's a fact,' Dr Tsoi said.
'If you asked the children, they would say it's just a game, but learning is very subtle, it's on a subconscious level.
'It's a reinforcing game. The game needs you to kill, to see the blood and it rewards you with points. It's not just watching, what we're talking about now is that you are walking along a corridor and killing people along the way.' In Hong Kong, where computers are becoming standard equipment in many homes, youngsters are able to spend hours at a time assuming the guise of a computer-generated killer. Industry observers in the United States estimate about 100,000 Americans have shelled out to buy the full version of Doom .
'I don't think that parents are aware of the violent effects of these games. They worry about their children's eyes from the radiation and they worry that they're not spending time doing their homework.
'In psychology textbooks you find children watching violence on television will exhibit more violent behaviour. It's a classic study and very well accepted,' Dr Tsoi said.
A group of computer game companies in Europe, called Elspa, operate a system of self-censorship to weed out and categorise games containing violence and nudity. Doom, distributed down telephone lines, has slipped through Elspa's net. A similar group of computer firms in Australia attempt to pacify public concern through self-censorship.