Buy a ton of Dragonflies and you will eventually get it.
How to unlock Flying
Finish the 1st world with 400 points to be able to fly.
Unlimited lives
Pause game play, then hold then hold L and press Up, Up, Up, Left, Left, Right, Left, Right.
Unlimited shield
Pause the game, then hold L and press Up, Down, Up, Left, Right, Down, Up.
Unlock Cheats
Collect 100 fireflies in a single level to unlock a new cheat.
Unlocking Cheats
Collect all 100 fireflies in every level.
Various Cheats
Collect all 400 fireflies in a level to unlock the corresponding cheat.
Level 1: Insect Eye . Changes your vision.
Level 2: Screen Switch. Reverses level.
Level 3. Auto-Hop. Hold D-pad to keep Zapper moving.
Level 4: Infinite Super Zap. Zapper always has a Super Zap.
Finding Secret Passages...