The Martians have landed. And they bought their computer-software consultants with them.

From a flying start less than four years ago when Space Invaders wasn't even a blip on the quarter-a-shot fun industry, the extraterrestials have taken over the Amusement & Music Operators Association trade show here.

It's tough to find a humanoid on any of the video or pinball games the manufacturers are showing, games such as Space Tactics, Missile Command, Space Firebird, Star Castle, Moon Cresta, Andrommeda and Fantasy 2000.

The Star Wars cathode-ray progeny have multiplied into infinity, with annual sales headed for the half-billion-dollar mark and five times that amount being thrown into the machines by the legions of junior space cadets.

It has become an industry dominated by the dreams of young men and the Japanese.

The average age of the engineers and programmers who are designing the new video games is 25, according to Steve Calfee, software manager for the video coin-operated games divison of Atari Inc.

Atari, owned by Warner Communications, is one of the few American firms only selling games developed in-house.

Space Invaders, which opened up the market, was brought to these shores by Midway Manufacturing Co., a division of Bally, via the Taito Group.

But the most popular game at the show was developed by a small firm, surprisingly an American one.

Deep Death could turn out to be the best thing that has happened to vicarious cannibalism since the University of Colorado's food service began Alfred E. Packer Day to celebrate America's first convicted man muncher.

In the tradition of Moby Dick, the gamesplayer becomes a shark in gastronomical pursuit of divers. Which is all the more fun because the divers are heard talking to each other, their heartbeats noticeably race as the shark gets closer and they emit a deliciously excruciating cry of pain when they're eaten.

The divers get smarter, though, as more and more of their comrades are eaten, for better or for worse depending on whose side you're on since the divers also can kill the shark.

For all of its growth potential, the industry could get stopped in its own tracks.

The supersophisticated video machines which are a joy to play are a pain to fix, and Bob Nims, president of the trade association, said they have not been able to train repair people fast enough. One of the few people who has actually giving lessons says he's only been home seven days in the last eight weeks.