By Darren Waters
Technology editor, BBC News website, in San Francisco
When Steven Spielberg announced he was entering the video game business many people assumed his first project would be a cinematic, visual-effects laden epic.
Spielberg was inspired to make family games
But his first game made under a multi-project arrangement with Electronic Arts, called Boom Blox, is a family-friendly puzzler for the Nintendo Wii.
"The first assumption is big, epic game... yadda yadda. [It's] not the game," says Louis Castle, who has worked closely with Spielberg to develop the title.
"But it's so not that product that the moment you see it, you know what you are in for.
"Steven has a multi-project deal with us and without giving too much away, there are projects much more in line with people's expectations, but those take a long time to make."
Spielberg got involved with EA because, says Castle, he is a gamer.
"He is a very big game player - not a lot of people know that. He loves playing games.
The game is a 3D puzzle action title
"He wanted to make them with some people he could trust. It seemed like a great partnership."
Spielberg was inspired to make a title for the Wii after playing on the console with legendary Nintendo developer Shigeru Miyamoto.
"He wanted to play a game he could play with his friends and family.
"He came to us with idea for the game and has been working with us on a weekly basis, overseeing the development of the game and working with me personally on the product.
"It's been a great kick."
Despite his commitment to film-making, both directing and producing titles, Spielberg has been dedicated to the development process.
"Steven will come in and tell us: 'These are kind of ideas I'd like to get to'.
"We brainstorm about what that might be, we might do some quick drawings on a whiteboard and then he goes away and does his stuff like making movies and saving the world.
"A week later we review the progress we have made and talk about what we do next. It's literally a very iterative process and we work very closely together."
Boom Blox uses the Wii's innovative controller to give players freedom to wreak havoc in the game.
"Steven wanted to make a game where the complexity and challenge of using your brain to look at three dimensional puzzles, and throw objects at it, and knock them over, was intriguing enough for adults to be interested.
"And at the same time this kinetic, visceral feeling would be attractive to children as well."
Castle adds: "As Steven would say: 'Kids just like to break things'."
The development team spent a long time working on the control system for the game.
Spielberg came up with the idea of the game
"We brought in the best computer scientists and we working on analysing the data you get from the Wii remote," says Castle.
"That was actually a very, very difficult problem involving lots of calculus.
"So many Wii games record just what the Wiimote is doing without much thought about or at least computation about what it was intended by the player.
"We've put a lot of thought and energy into what was intended by the consumer."
Spielberg's skill, says Castle, is to understand the player.
"More than anything he gets people. I have made a lot of games, more than a hundred and I am quite accomplished in this field, even I don't have that kind of instinct.
"Steve's instinct on people is incredible. He really understands what they are going to say about the game and what they are going to enjoy about it."
Castle is at pains to emphasise that Spielberg's attachment to the game is no marketing hook.
"This collaboration is not about attaching Steven's name to a game to make it sell. This is a creative collaboration between people in very different entertainment fields trying to make a product that will appeal to a very broad audience.
"We're making Steven's game and of course he's going to talk about it because he is excited about his game."