Full list of all 35 Nicktoons MLB achievements worth 1,000 gamerscore. It takes around 6-8 hours to unlock all of the achievements on Xbox 360.
Have a 1, 2, 3 inning with a single pitcher in any single-player mode
Hit a walk-off home run
Go six or more innings and allow less than four earned runs with your starter
Have your starting pitcher go the distance in a 9-inning game
Pitch a perfect game (9-innings)
Have a single pitcher record at least 18 strikeouts in a single game
Win by 10 or more runs
Win by only hitting singles
Win a 9-inning game in a single-player game
Win the Tournament
Pull off a Double Play
Hit for the cycle
Have a single player account for 10 or more RBI in one game
Have all starters on your team earn at least one hit in Single Player mode
Chase the opposing team's starting pitcher in the first inning
Hit consecutive home runs with the same player in two at-bats in the same game
Make it through a game without falling behind once
Hit a home run with a pitcher
Win a Single-Player Game
Win a 9-inning game in Showdown Mode
Win a Distance Derby Round in Single Player
Hit a Grand Slam
Defeat all the American League teams
Defeat all the National League teams
Unlock all baseball cards
Throw a turbo strikeout
Hit a turbo home run in the Poseidome
Hit a turbo home run in Air Temple Courtyard
Hit a turbo home run in Frosty Freeze Field
Hit a turbo home run in Ghost Zone Stadium
Hit a turbo home run in IRKEN FIELD
Hit a turbo home run in Yolkus Stadium
Load the Bases
Earn a multi-hit game with one player
Gain an RBI from a bunt