Pac-Man Party centers around a board game where Pac-Man and other characters from his game try to collect the most "cookies." It's what Pac-Man has been doing since the original game where the yellow guy goes around the screen eating what people have dubbed as everything from dots to pellets. But here, they're cookies, and collecting them is what wins the game.
Story Mode can be played with a single player, but it isn't much of a story. You go around the map playing the game, landing on spaces, playing mini-games, and battling your opponent. When you beat a board, you'll get a short story sequence, pretty much entailing the ghosts stealing or otherwise withholding a cookie recipe from Pac-Man. Pac-Man does meet some new characters along the way, however, including a fox (or cat?) named Patra from a land that looks a lot like ancient Egypt.
The board game itself is a mixture of a lot of different board game concepts. You need to collect castles, which pay you more, the more you own. You can also steal away another player's hard earned work of building a huge castle in an instant by choosing to battle them with a mini-game. There are also some special items like hover boots that help out the person in last place, so the game doesn't get to be an impossible race of catch-up for players that aren't good with the dice. Of course, a big advantage that a video game board game has is that special spaces can be animated, adding a bit more interest to moving around the board.
There's a nice variety of mini-games. You'll do everything from stacking ice cream cones to racing, to painting a canvas. I didn't get any repeats in my playthrough of the whole game, which is pretty impressive. It's just one of the ways this game shows it's not simply a piece of shovelware, there really is a lot that went into it. In addition to the mini-games, three classic arcade games are included: Dig Dug, Galaga, and of course, Pac-Man.