SEGA Superstars Tennis
45 Achievements
1,000
20-25h
Party Time
Play each type of Ball Game Multiplayer
30
How to unlock the Party Time achievement in SEGA Superstars Tennis - Definitive Guide
You can set these up in local multiplayer with a second controller and power through them in short order. You don't need to win the games, just play them. The Achievement will unlock as soon as the last one finishes loading, which leads me to believe that you don't actually have to finish a full game of each type, just enter them and quit back out.
For this achievement you need to have two controllers hooked up to your Xbox 360, and you also need to have unlocked all the ball games (Please see the "Score Attacker" for means on how to unlock all the ball games).
Once you have those two things, you may proceed onto the multiplayer ball games. Select Games from the main menu, and then select multiplayer. Press on the second controller, and select your characters. Go to each one of the 8 ball games, you don't have to do anything while playing you can just sit there and let the game end, or you can play, that's up to you. The only ones you're going to have to do something in is the Super Monkeyball game, the Virtua Squad game, and the Puyo Puyo game. After you're done going through all 8 games you will unlock the achievement.