Since I watch the Mariners all the time, I can tell that EA Sports has done their homework. From Ken Griffy Jr. and his homerun trot, to Jay Buhner's batting stance and Alex Rodriguez's underarm throw to first. Pitching is straight forward in the game. Above your pitcher you see your available pitches and chose which one you want to throw. At higher difficulties don't be surprised if your pitcher throws a pitch in a location you don't really want.
Batting has two difficulties to chose from.
Choosing between a power swing and a regular swing is as easy as using the right or left mouse button. For those skilled enough to use it, you can even check your swing by pressing the other button. On the more difficult setting, you have to move the target around to make contact with the ball. The computer isn't going to have any problems with hitting, so you might as well enjoy the game and use the easy setting. Fielding with the mouse is pretty simple in theory, but can be a challenge at times.