Hold  +  and press [Left], [Right], [Up], [Down],  on a game controller. Your next swing will be a homerun on contact, even if it is a bunt.
Home run sounds
Press A (air horns), D (whistles) while running around the bases after hitting a home run. Note: Set the Sound FX volume to maximum for best results.
EA Sports team
Right click the team at the season or homerun challenge screen to get the EA Sports team (home run challenge). On the season screen, the away team can be the EA Sports team and the home team. If right clicked about six times it will become the World team.
Catch a ball that is going over the fence or make a diving catch.
Make two diving or wall-climbing catches in a game.
Make three diving or wall-climbing catches in a game
Hit two homeruns in a row with the same player.
Score five runs with the same player in a single game .
Throw three strikeouts in a row with the same pitcher.
Throw six strikeouts in a row with the same pitcher.
Throw nine strikeouts in a row with the same pitcher.
Get sixteen hits in a game with a team.
Strikeout against the CPU six times.
Score four runs in a game with a team.
Score eight runs in a game with a team.
Score twelve runs in a game by a team.
Get two pick-offs, caught stealing, or outfield assists with the same player
Get more than eleven hits in a single game.
Steal three bases with the same player in a single game.
Hit a home-run with a player who weighs less than 150 pounds.
Hit three triples by a team in a single game.
Get eight hits in a game with a team.
Hit one home-run in a game with a player who weighs over 250 pounds.
Make three double plays in a single game.
Hit eight home-runs in a game with a team.
Steal six bases in a game with a team.
Get twelve hits in a game by a team.
Score ten or more runs to win a game.
Big League Challenge power boost
Hit ten consecutive homeruns in Big League Challenge to get a boost in power, which is noted with a flaming baseball.. With seven more consecutive homeruns, you will receive another boost in power, which is noted by a pulsating bat.
You can unlock certain stadiums by doing the following things. Note: These stadiums will appear after you complete the game you are playing in season or single mode in the stadiums option.
Space Stadium: Hit a ground rule double. Its easier to hit them on parks that have turf like the Skydome (Blue Jays) or Veteran's Stadium (Phillies).
Island Stadium: Win by three or more runs in Pacific Bell Park (Giants), Kauffman Stadium (Royals), Edison International Field (Angels) or Coors Field (Rockies).
Win a World Series in season mode only (not playoff mode) to compete in a world tournament versus the World Team, the Puerto Rico team, the Dominican team, the USA team, and the EA Dream Team. Note: The teams are listed in corresponding order. Win the championship versus the World team and move on to the Puerto Rico team. If you lose a game, you will not be able to play the other teams until you win another World Series.