LOS ANGELES(AP) There's no Burger King tie-in or special flavor of Mountain Dew. No commercial directed by Peter Jackson, or even an action figure. The run-up to "Grand Theft Auto IV" has been considerably less ballyhooed than last year's over-the-top "Halo 3" debut. Yet when "GTA IV" parks on store shelves on April 29, the latest entry in the controversial video game franchise could be the most lucrative launch in entertainment history _ and one that many people may not even know about. Analysts predict Take-Two Interactive Software and Rockstar Games' open-world, action-driving game will easily top last year's record-breaking $300 million first-week sales of Microsoft and Bungee Studios' first-person shooter "Halo 3" _ and without a similar marketing bonanza. With the launch of "GTA IV" on both the Xbox 360 and PlayStation 3, Rockstar is seemingly steering in one direction: the downlow. "Rockstar wants to control the message all the time," says Sam Kennedy, editorial director for the gaming site 1UP.com. "They want this to be seen and perceived exactly the way they want. That's why _ outside of the official trailers they released _ people haven't seen a lot of gameplay footage in advance of 'GTA IV' shipping. They want to build that hype." Take-Two and Rockstar declined to comment for this story, but following a 90-minute demonstration of the game in January, "GTA IV" writer and Rockstar vice president Dan Houser told The Associated Press that the infamous game developer, who's also responsible for the "Manhunt" and "Bully" games, was being overly protective for one very important reason. "We want people to be really excited and not know everything by the time they play the game," said Houser. "Of course, we want them to understand what they're buying, but we want there to be surprises along the way."