Activision Blizzard Inc's hugely anticipated Call of Duty: Modern Warfare 2 video game went on sale on Tuesday, welcomed by eager fans who lined up hours in advance of the release.

The first-person shooter game is set to be one of the biggest and fastest-selling titles in history, challenging records set by blockbuster releases from the Grand Theft Auto series.

This despite a dicey economic climate that is pinching consumer spending. Video game industry revenue in the United States, the world's largest market, is down 13 percent this year, according to industry tracker NPD.

But Call of Duty arrives amid high expectations and plenty of hype. Activision partnered with retailers including GameStop Corp and Best Buy Co for more than 10,000 midnight store openings in North America.

At the GameStop store near Union Square in New York City, around 80 mainly young people lined up Monday night ahead of the launch, some for two hours.

This is the only game I'm probably going to do this for, said Paola Altamirano, 21, who was waiting in the line. She said she planned to play Call of Duty against another friend online later that night.

With what Activision called a record level of preorders, there was little doubt about the strong demand for a game.

Gamers are enthusiastic about picking this stuff up at midnight, said Paul Swiderski, who works at the Union Square GameStop.

Analysts' sales estimates for the $60 game range from 11 million to 13 million units by the end of 2009. Call of Duty is likely to account for a sizable chunk of Activision's profits in the fourth quarter, analysts say, so there is plenty at stake in the launch.

Reviews of the game so far have been very strong. Website Metacritic.com, which aggregates reviews, gave it a rating of 96 out of 100, the highest among recent and upcoming releases.

HARD-CORE AUDIENCE

The audience for the latest Call of Duty -- the sixth installment in the franchise -- is primarily younger men, the gaming demographic that makes up the core of the estimated $50 billion global industry.

John Paneto, 20, was lined up outside a Best Buy store in San Francisco with about 10 others at around 10 p.m. Pacific Standard Time Monday (0600 GMT Tuesday). He said he had played a number of the other games in the Call of Duty franchise.

I'm going to be up all night playing it, until I crash, he said.

Analysts say so-called hard-core gamers are unlikely to be dissuaded from buying a big-name title by economic concerns, as some casual gamers are.

Activision Chief Executive Bobby Kotick said consumers are drawn into the game's narrative and visual effects, not just the chance to shoot at enemies.

You really do get a very visceral sense of what it's like to be in battle from playing this game, he said in an interview with Reuters Television. That's what the broad audiences are responding to -- rather than going to a typical action movie, this is like being in an action movie.

Call of Duty will have to turn in an impressive performance to top that of last year's mega-hit from Take-Two Interactive Software Inc, Grand Theft Auto IV. The title sold 3.6 million units on the first day and 6 million in its first week, for more than $500 million in sales.

Record or no, Call of Duty's launch injects much-needed excitement to the industry and its retailers, according to BMO Capital Markets analyst Ed Williams.

What makes this so important right now for the category is that it gets bodies back into the stores to go and buy the game and it should lead to what is a positive (sales) comparison in November and help to contribute to what could be a slight positive comparison in December, he told Reuters Television.

The game is facing little competition from other big-name titles. Industry watchers say Activision's rivals either pushed up the dates of their key releases or decided to delay them into next year.

Santa Monica, California-based Activision's stock, up more than 30 percent this year, slipped 12 cents, or 1 percent, to close at $11.42 on the Nasdaq.

(Additional reporting by Franklin Paul in New York; Editing by Gerald E. McCormick, Tim Dobbyn and Steve Orlofsky)

GameStop Video Launch