Press UP two times, Down two times, LEFT, RIGHT, LEFT, RIGHT, PROJECTILE, JUMP two times at the "Press Start" screen. A sound will confirm correct code entry. All skins will now be available at the "Unlockables" menu.
Damage the following Bosses with the corresponding technique. A sound will confirm correct code entry. Defeat the boss, then the next level will then be in Hard mode.
BOSS - TECHNIQUE Forest Shredder (Wolf Kingdom) - Reflect his dynamite back at his face. Wolf King (Deep Underground) - Wait for him to stand on top of a breakable floor block. Hit him until laughs, then drill attack the floor so that he falls. Axel Gear (Return To Zephyrus) - Have him get hit by the tracking purple ball attack that he uses.
ACHIEVEMENT - HOW TO UNLOCK Bunker Buster - Complete world 3. Burst Friends - Defeat 5 enemies in a single Rocket Burst or Drill attack. City Saviour - Complete world 1. Devotindos Defiler - Completed Arcade Mode on Hard. Elhorn Tourist - Completed all stages. Ferocious Flier - Completed 1.2 having defeated all enemies. Impatient Hero - Completed all stages below par time. Legendary Possum - Completed gold sparkster mode. Nimble Knight - Completed 3.2 without taking damage. Redoubtable Runner - Completed Arcade Mode on Hard within 60 minutes. Return of the Rocket Knights - Complete world 4. Spark Dog Millionaire - Completed Arcade Mode scoring 1,000,000 or more. Wolf Connoisseur - Completed 2.1 having collected all pickups. Wolf Kingdom Conqueror - Complete world 2. Woodland Bouncer - Defeat 3 enemies with a single reflected projectile. Zephyrus Saviour - Completed Arcade Mode on Normal.