The Bigs was a brief experiment that 2K Games tried out as a more arcadey, simpler alternative to their detail-heavy mainline MLB 2K series. It takes up where titles of the 90s like Baseball Stars and Extra Innings left off, with an MLB team and player license, but an easier style of play with players that are sometimes able to perform superhuman feats.
The game plays as normal with no real rule changes, but you generally only play five-inning games. As you get hits, runs, strikeouts and make great fielding plays, you accumulate points which can be spent to temporarily make a batter hit harder or run faster, or increase a pitcher's velocity. If you fill the points bar up, you can execute a one-at-bat "High Heat" mode (if pitching) or "Power Slam" mode (if batting.) High Heat increases the pitcher's velocity by 10 MPH and makes them near-impossible to hit, while Power Slam is basically a guaranteed home run so long as you make contact with the ball.
As you can imagine, games are much more high-scoring than usual, and it's multiplied by the ease of hitting. You don't have to adjust the batter or a cursor at all, you simply point the analog nub in the direction you wish to aim, and then as long as the ball is in the strike zone it's simply a matter of timing to swing as it comes in. Base-running is also automated with the exception of your current batter, who will always stop at first unless you press the analog nub to guide him in the direction of the next base. Surprisingly, fielding is NOT automated and is the weak point of the game engine. You're forced to use the analog nub to guide players toward the ball, and it's just too imprecise to have to adjust to the ball while in motion. I've had multiple doubles turn into in-the-park home runs on me because the fielders were just too clunky to get over to the ball, plus there's a weird delay when they throw the ball in as well. You'll make up for it at the plate though, where it's probably a little too easy to hit balls to the gaps ... homers are tougher as fielders can jump ridiculously high and knock the ball back into play even if they don't catch it, but with judicious use of the Power Slam you'll make mincemeat of the computer most of the time anyway unless you set the game to the highest difficulty. On "normal" difficulty on my second day of play I was shredding opponents 40-1 with the 2006 Pirates, to give you an idea.
The game's other weakness is a total lack of any kind of season or franchise mode. All you can do is play exhibition games, do a Home Run Derby, or "Rookie Challenge" which turns out to be the meat of the game and the replacement for a proper Season mode. Rookie Challenge has you create a player, then take them and their team through a limited season where you mostly play 3- or 5-inning games against opponents, just playing most of the MLB's teams 3 times. Some games you just have to win, some have conditions for your rookie like having to get at least one hit or drive in at least 1 RBI as well as winning. Rookies can also only be fielders, they can't be pitchers or catchers. Rookies get points for their in-game hits, runs, RBIs and great fielding plays, and periodically you do a training mode in one of the game's skills which nets you a pile of bonus points as well. You then assign points as you choose to the rookie's hitting power, contact, glove, throwing arm and running speed. With the ease of hitting, the fielding training modes actually become the hardest part of the game, thanks again to the janky analog nub.
The gameplay engine is solid, with only minimal annoyances; I just wish it was paired with an actual season mode. The game also was ported to the PS2, Xbox and Wii, so those versions might at least iron out the annoying fielding controls.