If you want to make an argument that sports games should be released biannually, look to Turn 10 Studios' Forza Motorsport franchise.

Since Forza Motorsport debuted on Xbox in 2005, the Forza series has steadily released a new entry every two years, with each title easily lapping the last.

In terms of innovation, Forza 3 has a reputation for being the franchise's smallest advancement to date. But after spending 15 hours with Forza 4, I feel confident saying that, if Forza 3 had some gamers feeling like the series was starting to spin its wheels, Forza 4 will convince car fans that Turn 10 Studios are one of the top developers in the sports industry.

Visuals

Forza 4 may be the Xbox 360's prettiest sports game. Each of the game's 500+ car models is stunningly accurate, right down to the fonts on dashboard displays. As a real-life driver of a 1994 Honda Civic, I was shocked to see that the interior of Forza 4's Civic is an inch-for-inch replica of the car I have sitting outside in my driveway.
 

With over 80 licensed car manufactures in Forza 4, chances are, your real-life ride is somewhere in the game. GMC trucks, Jeep Cherokees and Hummers even made it into this year's Forzacatalog, ensuring that the series is no longer just about sports cars and coupes.

Audio

Cars sound just as realistic as they look: muscle car engines roar violently like a jungle lion, while electric vehicles, such as the newly included Nissan Leaf, pur sleepily like a house cat.

The in-car music is a nuisance, with Forza's usual mix of electronica and techno beats, but as always, default songs can be turned off, letting your ears attune to the sounds of tires dying and engines grinding away.

Gameplay

A major complaint of past Forza games has been that the AI drivers felt too robotic. Turn 10 listened to the criticism, as Forza 4's computer cars make plenty of mistakes now -- misjudging turns, sliding off the course and even crashing all on their own!
 

Computer drivers are feisty, and will fight anyone who challenges their position. Gone are the days of the CPU sticking to an automated racing line and barely interacting with any other cars on the track. Career mode races against the AI feel tough but fair -- a great change from the demo's "too easy" medium setting and "too cheap" hard setting. 

Difficulty settings are still accessible in the career mode by selecting "Event List" instead of "World Tour." But simply playing through career using the World Tour feature makes for a fun, challenging experience.

Bugs/Glitches

Early reports from the Forza Motorsport forums reveal a glitch in the way Forza 4 detects some wheel peripherals, preventing players from receiving any experience points. Setting the wheel sensitivity to "270" seems to solve this problem, but nonetheless, it's a frustrating issue for wheel users.

Replay saves also seem a bit buggy, as one of my saved replays got stuck about 20 seconds into the race and refused to advance past that point on film. The online storefront seems to have some early-release quirks, too, as one of the tuning sets I bought and downloaded from another user gave me a "corrupted file" error whenever I tried to load it on my car.

Early Outlook

Forza 4 looks, sounds and drives like a dream, as if it was hand-crafted in the heavens by deceased racers like Dale Earnhardt, Kenny Irwin or Adam Petty. 

Gran Turismo, Need For Speed, whatever racing franchise you want to pick, they all seem far-behind the pace that Turn 10 has set with their latest Forza release.

Divorce your wife, put your kids up for adoption and send the dog to live with neighbors: Forza Motorsport 4 will be taking up every racing fan's full attention this Fall.