Despite the board parts being extremely boring, Mario Party DS is a very fun game.
1 - THE BOARD PART: Before going into a challenge, you've gotta wait through a boring board game like... errr... thing. It's really boring because it's a game of chance and it can take forever for your opponents turns to be over.
2 - THE LENGTH: It could last you a while if you actually want to go through and beat it 100%, but the main story will only take you about a day or two.
3 - THE DIFFICULTY: I said that the difficulty is just right, but it isn't, it's between hard and easy but is somehow closer to easy, meaning that it could stand to be more challenging.
But the game is still great and has ton's of replay vaue. (Even if it's not fun replay value) There are ton's of wacky challenges, some more entertaining than others, but whatever kind of game you like, there's sure to be something in here for everyone.
Chances are, once you beat the game once, you won't want to go through again. And if you think that you can replay minigames, think again. Almost everything requires two players. The only few things that don't is story and "Step It Up" minigame.
For beating the game with a certain character, you'll get a medal.(Example: Toad medal for beating the game with Toad) These medals are basically pointless however, and just seem like a sad attempt at adding length to the game.
Pros: Good graphics. Cartoony music. 8 different playable characters. 70+ minigames make it unlikely to get the same game twice within the first few levels. You can play old Mario puzzles. Great use of the Stylus. Some minigames are extremely entertaining.
Cons: Almost everything requires two players. Board parts are as boring as heck. There's replay value, but it's boring replay value.
I do enjoy MPDS, and I think that anyone with a DS should own it.