Here is the full list of all 30 Baseball Stars 2 achievements.
Win 5 games
Win a game without giving runs to the opponent
In single player mode, perform 5 straight strikes (pitcher)
Perform 10 homerun
Playing pitcher, hit 10 times the batter
Loose a game by 10 runs
End a game with 0 run
Win a game
In single player mode, eliminate 3 batters playing pitcher
Eliminate a AI player playing pitcher
Complete a game with a friend in hard mode
Playing pitcher, hit the batter
Play with all team of the Hard league
Play with all team of the Easy league
Perform 1 homerun
Eliminate a AI player with a catch
Win a game by 10 runs
Win 5 straight games
Win 15 straight games
Complete the easy league
Complete the hard league
Win 10 games
Win 20 games
Win 50 games
Complete a game with a friend in easy mode
Win the Easy league
Win the Hard league
Complete Easy league with each team
Complete Hard league with each team
In single player mode, perform 10 straight strikes (pitcher)