Ridge Racer is the fourth title in the Ridge Racer series, developed exclusively for the PSP, and features new visuals powered by goraud-shaded polygons. The game retains the same arcade gameplay as the first game, while offering a more refined appearance. The focus of the game is on the Real Racing Roots '99 championship, where players compete in three heats with seven races, culminating in a grand finale at a speedway during New Year's Eve. The player chooses one of four teams available, each with its own strengths and weaknesses.
Players start by selecting a team and car maker from Lizard , Assoluto , Age Solo , and Terrazi . Each car type has its unique characteristics, such as drifting wildly on corners or requiring more breaking and careful trajectories. The player earns cars by completing races and can unlock up to 320 different vehicles.
R4 Ridge Racer Type 4 also includes an extra disk with the original Ridge Racer in higher resolution. The game was initially released on September 1, 2005, and was later sold as a bundle along Namco's innovative Jogcon controller. The game features modes such as time attack and split-screen versus mode, where players can compete against each other in local multiplayer.