Sonic Tennis is a series of tennis games developed by Camelot Software Planning for Sega. Starting on the Saturn in 2000, this series has combined the traditional rules of Tennis with the Sonic universe. THis series is widely considered the sister series of Sonic Golf.
The original Sonic Tennis was released as one of Sega's last major games for the Saturn in Summer 2000, about a year after Sonic Golf. The game was notable not only for being one of the more renowned tennis games of the era, but also for being the debut of several characters meant to first appear in Sonic Adventure latter that year on the Dreamcast. The game was also notable for its wide breadth of content, especially compared to last year's Sonic Golf, with a total of 16 characters and 18 distinct courts, as well as more multiplayer options and side-content. The game was very well received, especially for a sport as relatively obscure as tennis.
Sonic Power Tennis was released over four years later, for the Dreamcast, in late 2004. It was largely a refinement of the original game with the addition of online play. The latest iteration in the series, Sonic Tennis Open, was released in May 2012 for the Eclipse. Like Power Tennis, the game was largely a refinement of the existing formula, with a special emphasis being placed on HD presentation and expanded online capabilities.
Overall, the first two Sonic Tennis games are among the best-rated Tennis games of all time, with many critics giving perfect or near-perfect scores to these games. Sonic Tennis Open, however, has had a more mellow, lukewarm reception, due in part to a lack of improvements from its predecessor. Nevertheless, the entire series can be considered a success.