Forza Horizon developer Playground Games has elaborated on its decision to go against the parent series' core tenet of 60fps and produce a racer which runs at 30fps.

The decision to sacrifice framerate was done to give "precedence" to certain features last year's 9/10 grabbing Forza Motorsport doesn't yet have - such as a full day/night cycle and an open world.

"This is something we talked about with the Turn 10 guys right at the start," said Playground Games' Ralph Fulton to "60fps is something that's important to the mastery of Forza Motorsport. But what we want to do, in terms of the open world, in terms of the day/night cycle, in terms of the many technologies we've layered on top, really means that we couldn't do all those things and still run at 60fps."

"What it came down to was a choice of what's really important. What we alighted upon was that the immersion of the world, its believability, and all of the features and technologies we're packing in take precedence."

Fulton also explained what exactly was under Forza Horizon's impressive bonnet during an E3 2012 presentation of the game.

"We have a real-time dynamic sky and cloud simulation, that's always changing and always evolving. On top of that we have a dynamic sun, that moves across the sky casting shadows from every object from within the world - even the cars. Finally we have atmospheric scattering, and that picks out individual particles from within the atmosphere and really deals with how light creates depth and realism within the view."

"We knew right there and then we were going to have to invest some serious time in creating technology to adequately render those views. Now Forza 4 has great vistas, right? You've seen the Alps track. The difference in [Horizon] is that if you can see it, you can drive to it. So we had to create what we call uber-LOD technology. Basically that enables us to draw up to 20km into the distance while still maintaining the high level of visual fidelity you've come to expect and demand from Forza games."

Forza Horizon will be released for Xbox 360 on October 23.

Elsewhere, you can check out everything we know about Forza Horizon.