Sega Superstars Tennis is a crossover tennis game between various Sega properties developed by SUMO Digital and published by Sega. It was released for the Playstation 2, Playstation 3, Nintendo Wii, Xbox 360, Nintendo DS and Mac OS X in 2008. The game is the second installment of the Sega Superstars series, after Sega Superstars.
As in a tennis game, the player(s) must hit the ball back and forth until one side misses it. The matches can be either single matches involving two players, one against each other or double matches where two pairs confront each other. To win a game, the player must win two matches, each match is won by scoring more than 40 points.
In the tennis matches, there is a yellow star underneath the characters, which is fullfilled as the character hits the ball to the other side. Once this star is completely fullfilled, the character will be able to use the Super move, a special ability which assists the characters at scoring points for a limited time, by making them cause an effect on the opponets which will make it harder for them to hit the ball back.
The game also features several Sega thematic mini games involving tennis, some examples include a House of the Dead mini game where the player must kill the zombies by shooting tennis balls at them and a Puyo Puyo mini game where the player must shoot the tennis balls at columns of Puyos.
- Matches: The player can challenge one or two characters for a free tennis match.
- Tournament Mode: The player takes a series of matches against random opponents.
- Superstar Mode: The player can take missions in many SEGA worlds, including tennis matches, tournaments and minigames based on SEGA games and unlock more characters and tennis courts.
The game has a total of 16 playable characters from different Sega games, with 8 of them being unlockables:
||Starter Character.||NiGHTS racket is purple and has a purple rhomb on its net, most likely referencing the red ruby on NiGHTS chest.||
|NiGHTS will make the opponents teleport when they hit the ball back.|
||Unlocked by winning the second mission in the world of NiGHTS into Dreams in the Superstar Mode||Reala's racket is purple with a yellow stripe and it has a waning moon on its net.||
|Reala will make the opponents dizzy when they hit the ball back.|
- Aqua Garden (NiGHTS: Journey of Dreams):
Description: The court is located inside a tholos marble temple with a shallow water pool. The temple had previously appeared during the second lap of the Aqua Garden level from NiGHTS: Journey of Dreams. This tennis court is also used for the Puyo Puyo minigame. This tennis court is unlocked by cleaning the first mission in the world of NiGHTS into Dreams from Superstar Mode.
- Sweeping Seashore.
- The Amazing Waters (Unlockable).
- She Had Long Ears (Unlockable).
- Paternal Horns (Unlockable).
- Green Hill (Sonic the Hedgehog series).
- Scrap Brain Zone (Sonic the Hedgehog series).
- Monkey Island (Super Monkey Ball series).
- Shiubuya DownTown (Jet Set Radio series).
- Spaceport9 (Space Channel 5 series).
- Carnival Park (Samba de Amigo series).
- Curien Mansion (House of the Dead series).
- Carrier Zone (After Burner series).
- Coconut Beach (Outrun series).
- NiGHTS' super move could be making a reference for their two main attacks, the Drill Dash and the Paraloop. When NiGHTS hits the ball during their super move, they will make the ball travel in a corkscrew loop, which could be a reference for their Drill Dash attack and when the opponets hit it back, they will teleport for a random location of the court, which could be a reference for the Paraloop.
- During the NiGHTS super move cutscene, it's possible to notice one of the Nightopians is crying.
- In the Nintendo DS version of the game, Reala says "Beadichinoa NiGHTS!" before the match. This is a reference for his pre-battle dialog from NiGHTS into Dreams.
- The Nightopians are completely absent from the Nintendo DS version of the game.
- This game marks Reala's debut in the Sega Superstars series.