"Sonic Rivals 2" has four main Single Player modes. Story Mode is the main single player mode. Players go through each of the game's battle modes and levels to advance the plot. Each zone has three acts and a boss, with the exception of the final zone. The characters are divided into four teams (Sonic and Tails, Shadow and Metal Sonic, Silver and Espio, Knuckles and Rouge) and each character has their own story. The game introduces a new mode called Free Play. In this single player mode, players can choose any one of the eight characters and play through the zones in traditional 2D Sonic fashion. They can also try Time Attacking, or finding the ten hidden Chao in the levels. There are no opponents for this mode. This is a first for many of the characters featured. In addition, players can also try the Cup Circuit and Single Event modes. Races and battle can be customized in every aspect, and players can try to earn cards by completing challenges. There are 150 different cards to collect, and each is tied to a certain achievement. For example, getting an S Rank in Knockout Mode unlocks a card of Mephiles the Dark. The cards themselves contain art from various older "Sonic" games, and can unlock things such as alternate suits for the characters. Unlike the first game, only one card is needed to unlock a suit; and each character has four suits instead of the original three. The cards also unlock the Cup Circuits, and Chao Detectors for the Zones.