Super Monkey Ball
• Extra or unlimited continues
• Extra stages

• Extra or unlimited continues
After you've unlocked the three mini-games, you can get additional continues for each 2500 play points you collect. Most importantly, when you work you way past nine continues, you are bestowed with unlimited continues. This should help in beating Expert mode. Now if only someone could do it without dying...

• Extra stages
Beat the 10 beginner, 30 advanced or 50 expert stages without dying and you will be treated to the extra stages for that level. There were three extra stages for beginner, and if you think I've beaten advanced without dying yet, you're crazy! However, it's safe to assume that there are at least three there as well.
The extra stages are unique in their challenge and can be quite difficult (even on beginner mode). Have fun!