Mario Party games have constantly been getting lower and lower reviews even though the general quality and enjoyment from the games has not dropped off. The main reason for this (I suspect) is that a lot of reviewers have played every game in the series quite heavily (in order to give a reasonable review) and they're playing the game in a way which was not intended.
Mario Party is primarly a local multiplayer game, the true enjoyment of the game comes when you have 4 people (or 8 people on teams of two) playing the game together locally; the nature of the game makes this (fairly) easy to accomplish being that people of varied skill level can play the game together and enjoy it. Playing these games single player (as you're likely to in a review) is never all that much fun.
