Aquadome Stadium:
Hit a homerun into the water at Frasier Field, Steele Stadium, and Gator Flats.

Baseball Darts Mini-game:
Score a 40 or better in the fielders challenge.

Mr. Clanky:
Complete Mr. Clanky's coaching box.

Pedro Martinez:
Throw a shut-out.

Mike Piazza:
Hit a grand slam.

Barry Dejay:
Enter HOOPS as a new coach name to unlock Barry Dejay.

Championship game stadium:
To get the field that you play the championship in, simply win the world series 
undefeated (by going 4-0 in the series) and then create a new coach and team 
then choose that field as your home field. (this is the stadium where you play the 
all-star game at also, it is the one with the hot dog holding a bat, behind the center 
field wall.)