Sega Superstars Tennis is a tennis video game developed by Sumo Digital and published by Sega. The game was released on March 17, 2008 in Europe, on March 18, 2008 in North America, and on March 27, 2008 in Australia. The game includes 16 playable characters and 10 courts from Sega franchises. In total, 15 Sega franchises are represented in the game.
Superstar Mode allows the player to play missions 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.
Source: Wikipedia, "Sega Superstars Tennis", available under the CC-BY-SA License.