Rocket Knight Cheats

Trophies
There are 7 Bronze Trophies, 4 Silver Trophies, and 1 Gold Trophy.

Burst Friends (Bronze): Defeat 5 enemies in a single Rocket Burst or Drill attack
Devotindos Defiler (Silver): Completed Arcade Mode on Hard in a Single Playthrough
Elhorn Tourist (Bronze): Completed all stages
Ferocious Flier (Bronze): Completed 1.2 having defeated all enemies
Impatient Hero (Silver): Completed all stages below par time
Legendary Possom (Gold): Completed Gold Sparkster Mode
Nimble Knight (Bronze): Completed 3.2 without taking damage
Redoubtable Runner (Silver): Completed Arcade Mode on Hard within 60 minutes
Spark Dog Millionaire (Silver): Completed Arcade Mode scoring One Million Points or more
Wolf Connoisseur (Bronze): Completed 2.1 having collected all pickups
Woodland Bouncer (Bronze): Defeat 3 enemies with a single reflected projectile
Zephyrus Saviour (Bronze): Completed Arcade Mode on Normal

Unlocking Hard Mode
Here is a list of the special techniques (Things you have to do to a boss before you beat them) in order to unlock Hard Mode for the next set of levels. Whenever you complete a special technique, a sound effect will play in the background.

Hard Mode: Deep Underground: When fighting the Wolf King, destroy one of the crumbling platforms when he's standing on it, so that he falls to the floor below and gets damaged.
Hard Mode: Return to Zephyrus: When fighting Axel Gear, catch him in the blast of his glowing purple orb attack.
Hard Mode: Wolf Kingdom: When fighting the Forest Shredder, reflect one of the sticks of dynamite it throws back at its face.