Get different shot capabilities
Go to the shop and purchase:

Bazooka Shot
Buy fast reload and power for 50,000 points

Rifle Shot
Fast speed and very powerful Rifle for 100,000 points

Always invisible
Collect 50000 points and buy CheatCode Set a from the shop.

Always land no matter what
Collect 50000 points and buy CheatCode Set a from the shop.

Full SBK bar
Collect 50000 points and buy CheatCode Set a from the shop.

New shots:
The following new shot types can be purchased at the shop.

Bazooka Shot: 50,000 points.
Rifle Shot: 100,000 points.

Cheat Code Set A:
50,000 points (Always Invis, Always Land, Full SBK)

Play as Max:
Defeat Max when he randomly appears in World Tour mode grade C to unlock him for purchase at the shop for 50,000 points.

Play as Jack Frost
Defeat Jack Frost when he randomly appears in World Tour mode grade B to unlock him for purchase at the shop for 75,000 points.

Play as Black Frost:
Defeat Black Frost when he randomly appears in World Tour mode grade A to unlock him for purchase at the shop for 200,000 points.

Unlocking Higher Grade Difficulties
When you first start the game, you'll only be able to choose Grade C courses, which are the easiest to complete. However, if you manage to beat the Grade C courses, you will unlock Grade B. Should you finish all of the Grade B courses, you'll be able to play the Grade A courses, which are the hardest in the game.

Grade A Courses - Complete all Grade B Courses
Grade B Courses - Complete all Grade C Courses