Test Drive Unlimited, distributed by ATARI, is an arcade-style racing simulator that features over 125 licensed sports cars and motorcycles and a terrain modelled after the Hawaiian island of Oahu. The island features over 1600 km of roads and highways. Test Drive Unlimited is the latest installment of Test Drive, one of the longest running racing games ever.

Test Drive Unlimited, the player is able to drive both on-road and off-road, challenging any racers they encounter. Oahu is modeled to within a meter of detail of its real life counterpart, as the developers have used satellite imaging for precision modeling. The terrain differs from rainforest and mountains to sandy beaches and Hawaii's capital city, Honolulu.

Single-player game
The game begins by purchasing a car and a house. The player is then free to explore the island; as this happens key locations on the map are revealed. These include:

Car/Bike dealerships
Car rental agencies
Tuning Shops
Real Estate Agents
Clothing shops
Challenges, including:
   Race vs CPU cars 
   Time challenges 
   Speed challenges 
   Hitchhikers (male)
   Top Models (female)
   Courier (Package Transport) 
   Vehicle Transport

Success in challenges is rewarded with in-game money, or in the Hitchhiker and Top Model challenges, clothing coupons. Using these coupons, you can buy clothing for your character at the many branded clothes shops on the island. Money earned may be spent on buying new vehicles, renting cars, upgrading cars and buying houses. Players can acquire a total of 90 sports cars from manufacturers including Ford, Chevrolet, Ferrari, Maserati, Lamborghini, Audi, Dodge, Pagani, Aston Martin, Mercedes-Benz, Lotus, TVR, Jaguar, McLaren and Saleen, as well as motorbikes from Ducati, Kawasaki, Triumph and MV Agusta.

Multiplayer game
The multiplayer component (branded as M.O.O.R or Massively Open Online Racing) works seamlessly in the game, but only if the initial user profile was linked to a GameSpy ID.

With a multiplayer ID, the following challenges are also available:
   Race vs other players 
   Challenge players to race challenges you created yourself
   Attempt other player challenges

It is also possible to create an immediate, ad-hoc race against another player by flashing headlights at their vehicle.

Players may create and join clubs which help organize player events.

From your houses you can view your progress in the game, news items such as achievements and club activities as well as a place to trade your vehicles with other players through a central "clearing house"-style interface that lists the vehicles for sale along with class, mileage, specification, and price information.

The game is extremely addictive and requires a fair amount of dedication to complete, so be warned - if you buy this game, be prepared to write off a few week-ends and late nights. If you don't have ADSL or iBurst, I would suggest you seriously look at getting it, as the game can only be fully appreciated in online mode with a stable, fast connection.