Mario Party 8 - Play as Blooper or Hammer Bro

Bowser's Warp Orbit:
Complete the Star Battle Arena with any character.

Crown Showdown:
Unlock a mini-game in the Four Player, 1 vs. 3 Player, 2 vs. 2 mini-game and Duel mini-game categories.

Flip Out Frenzy:
Unlock a Four Player mini-game.

Test For The Best:
Unlocked in the Fun Bazaar.

Tic Tac Drop:
Unlock a Duel mini-game.

Minigame Wagon:
Successfully complete Star Battle mode to be able to buy mini-games at the Minigame Wagon.

Easy dart shooting:
When using the dart wheel wait until the target you want is at where 9 is on a normal clock an throw the dart then, its not guaranteed but works about 8/10 of times.