Peter Molyneux has learned a lot from his 30 years in game development, but what he is seeing now in the free-to-play arena--and experimenting with in Curiosity--has him excited about its viability as a tool to make better games, providing that F2P is at the beginning of the discussion.

"You can't introduce free-to-play mechanics to a title six months after it's released," he said in a keynote at a F2P Summit conference in London (via The Guardian). "It's got to be part of the design. It can't just be crammed in there later on." He added that there have been some bad examples of developers putting in-app purchases into games that aren't designed for them, or milking consumers for cash under the F2P banner.

Free-to-play also eliminates one of the nagging problems in game development: "this terrible phrase from marketing: 'Can we have a demo of the game?' That's another thing that free-to-play did. The game itself is the demo, and the demo is the game," Molyneux said.

For Curiosity, Molyneux said the game was too successful in the beginning and they had to rush to solve it, but now, as people near the core for the final unveiling, his team at 22Cans is starting to evaluate its success. While some of the cheaper in-app purchases have been the most successful, he said that the $77,000 Diamond Chisel, which would have chipped away at the cube in massive chunks, never made it into the game, but was really meant to be just a tease.

"With the Diamond Chisel, our ambition was to charge an impossibly-high amount--so high that no one in the world would buy it," he said. "It was more the psychology of knowing that this hugely valuable thing was there ... But when we submitted the app to platform holders like the App Store, they turned around and said 'Oh my goodness, you can't charge that amount!'"

Of course, when you read stories about kids charging up huge bills on accounts charged to their parents' credit cards, that may have been a wise move.