Unlock Star Ball:
Get A Gold Trophy In Star Cup (Normal Mode)

Unlock Watermelon Ball:
Get A Gold Trophy In Flower Cup (Normal Mode)

Unlock Yoshi Egg Ball:
Get A Gold Trophy In Mushroom Cup (Normal Mode)

Unlock Blue And Silver Ball:
Complete All of the Training Mode

Unlock All Silver Ball:
Get 2000 Points On Your Ranking Score

Unlock Dice Ball:
Get A Gold Trophy In Flower Cup (Hard Mode)

Unlock Cheep-Cheep Ball:
Get A Gold Trophy In Mushroom Cup (Hard Mode)

Unlock Goomba Ball:
Get A Gold Trophy In Star Cup (Hard Mode)

Unlock Gold Ball:
Get 5000 On your Ranking Score

Unlock Soccer Ball:
Get A Silver Trophy In Mushroom Cup (Hard Mode)

Unlock Black And Red Ball:
Play On Stage Rainbow Ship On Expidition Mode Without Getting
Any Coins And Win The Game

Unlock Purple And Orange Ball:
Play Bowsers Castle For The First Time In Expidition Mode

Unlock Yellow And Green Ball:
Play Daisy's Garden For the First Time In Expidition Mode

Unlock Red White And Blue Ball:
On Any Tournament Match Win by Using ONLY Charged Shots

Unlock Rainbow Ball:
Win 5 Time In Wireless Expidition Mode

Unlock Pumpkin Ball:
Lose 5 Time In Wireless Expidition Mode

Unlock Spiked Bal Get A Gold Trophy In Star Cup

To get Cactuare, you have to dribble the ball on his head (not tested) in the Glare Desert. To get it, you need to score 800 points in the Star tournament (I don't know if you need to do it in the Hard level.

If you have trouble like me with beating teams with strong good players like me you should do what I do. I pick the player on my team. I can not beat Mario Peach and Bowsers team in the Rainbow cup on hard difficulty but using this cheat means three powerfuls players you don't have to beat. Hope this helps!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!