While the player's bodies may not be supported by much, the game is supported by a number of fairly deep play modes. All of the MLB players and teams are represented and if you don't happen to have a favorite, you can always create your own. There's no roster support through online downloads, though you can make sure all of the team's rosters are up-to-date through Arrange Mode. Additionally, you can nuke every team's roster and force them to start over with Dream Draft.
While modes like Season are fun, Success and MLB Life modes make up the core MLB Power Pros 2008 experience. In Success, you create a player and play through his career as a rookie on a Double A team. During your time with the club, you can train up your player, upgrading his stats as well as unlocking new moves based on his position, such as additional pitches or new batting techniques. All work and no play makes whatever you choose to name your character a dull boy, leading to off-the-field experiences.
The entire mode plays out as a story mode and gives you the opportunity to interact with teammates. These interactions push the game along through the main story, as well as allowing you to unlock new items that will help you improve your stats and skills even more. Though there doesn't seem to be a set way you "have to" go through Success - if you want to just focus on skills you're able too - it feels a little too scripted and predictable at times. Your team is destined to lose some games, mostly for dramatic effect, so it feels like you're just playing through a slightly interactive movie. The pacing is brisk, to the point where some information will fly past you faster than you can process it, though since you're only playing baseball when your name comes up on the roster, most of the time it feels like you're just clicking through menus.
You goal in Success is to make it to a Triple A team and eventually land a spot in the Majors, which is where MLB Life takes over. MLB Life is similar to Success, only now you have to deal with the trials and tribulations of playing as a Major League player. There are, of course, situations like training and making sure you're a starter, but you'll also have to deal with finding hobbies, deciding which charities to support and so forth. There's even a mild dating sim thrown in. The situations have a definite Japanese quirkiness to them, though they are enjoyable and seem to represent several real-life situations pretty well. Decisions also influence your character's development as a player, adding a surprising layer of depth and strategy.
MLB Life isn't just limited to your own created character. If you want, you can also play as any of the current MLB players. You can start up a career in MLB Life without going through Success, though it isn't as much fun if you do.
You'll earn points throughout each mode, which you can spend on cards. These aren't vital to the game but, like Achievements or Trophies, are oddly effective motivational tools.