The game includes two characters from the Jet Set Radio series:
The game also includes 14 SEGA characters from different games.
- Sonic the Hedgehog
- Miles "Tails" Prower
- Amy Rose
- Shadow the Hedgehog
- Doctor Eggman
- Ulala (Space Channel 5)
- Pudding (Space Channel 5)
- Aiai (Super Monkey Ball)
- Meemee (Super Monkey Ball)
- NiGHTS (NiGHTS into Dreams)
- Reala (NiGHTS into Dreams)
- Amigo (Samba De Amigo)
- Gilius Thunderhead (Golden Axe)
- Alex Kidd (Alex Kidd)
- Superstar Mode allows the player to play missions in the worlds of sega which include exhibition matches, tournaments and tasks based around a specific Sega game including Sonic the Hedgehog, Puyo Pop and Virtua Cop. Completing missions unlocks items such as courts, stages, soundtracks and characters.
- Exhibition Mode offers the chance to challenge a character to a match on one of many courts, including Sonic's home court of Green Hill Zone, or Amigo's Carnival Park court. Whichever court is chosen, there are a host of Sega celebrities cheering them on from court side.
- Tournament Mode allows the player to play in a series of matches against opponents chosen at random by the computer in an arena also chosen at random.
- There are several playable minigames in Sega Superstars Tennis, including ones from Sega games such as a House of the Dead meets Space Invaders game, in which the player has to hit moving targets in the form of zombies, a Space Harrier game, a Puyo Puyo game, and a Virtua Cop game.
- Each character has their own unique 'special attack' giving the player more chance of scoring a point. For example: Gilius throws a magic bottle in the air and covers the opponent's side with thunderbolts, if they touch one the character will be stunned for a brief moment, or Sonic's signature "Super Sonic" attack, which causes the tennis ball to zig-zag in various directions around the court when he hits the ball.
The PlayStation 3 and Xbox 360 versions both have online play, while the Wii version has three different control schemes (motion control, Wii Remote sideways, and Wii Remote with Nunchuk). The Nintendo DS version of the game can be played with the standard control pad, or utilize the stylus.
There is one court featured in this game from the Jet Set Radio Series