Secret In Pyramid Area

When you reach the Pyramid (before you fight Sharaku Hosuke), you will notice there are about 4 "pits" that you can hide in, so the rolling things can't harm you. Go to the one nearest to the top and go straight to the wall, then jump, and, quickly, jet down to see that you have passed the floor. Walk to the right and you will see a strange creature that looks like a cross- breed between a Shy Guy and a puppy. Hit it once (but not in a combo) and it will let out a small heart that replenishes health. Kill it and it will let out a big heart that also replenishes health. To go back, go left and jump back to the place where you passed the floor. You can go back as many times as you wish, but to respawn the creature you have to retry the level or leave the level and go back.

Steps To Completing Level 0-4

1. Meet Magma first! If he's already in the Omega Factor, you don't need to visit 
the elevator stage again.
2. Go to stage 0-4 and meet Boon.
3. Go to the Great Pyramid stage (6-something) and talk to Don Dracula. He'll 
tell Atom about Sharaku's secret.
4. Return to stage 0-4 and you'll get Boon for the Omega Factor.
5. Check your Atom Heart (or Omega Factor) by pressing the select button. 1. If 
Blue Knight and Duke Red do not have colored faces, go to stage 0-2. 2.. If Boon 
doesn't have a colored face, check the section for stage 0-4 and follow the steps 
to finish ALL events. Stage 0-4 is officially cleared when Boon has a colored 
face.

Unlocking Stage 0-3

You MUST successfully complete ALL of the events related to level 0-2 and 0-4 to unlock level 0-3. Note: The "eye" Kennedy refers to is related to Boon's work as an archaelogist (hint: Sharaku)

Meet Fumoon Stage 3-3

If your atom is charged to level 3, you will be able to see the level without the steam obsructing your view. At the start of the stage, go down and proceed towards the right until you can't move any further. Try jumping and you'll see a platform with the laser/plasma traps placed underneath it. Stand on the left-side of this platform and punch/shoot like crazy. You'll meet Fumoon eventually.

Level Select

Successfully complete the game on Normal mode.

Unlock Sharaku Hosuke

Your second time through the game successully complete level 8-4 which will be accessible. At the end of the game, watch the credits but DO NOT press start. You must wait for a certain event to occur. Once it does, Sharuku will be available in the chararcter selection list. Also unlocking Sharaku will also remove the exclamation marks on Ham Egg and Don Dracula.

Undefeatable Pook

The real Pook is with Sharaku. Since Sharaku knows about time-travelling and soul- transcendental, it doesn't really matter how many times Astro fights Pook. Sharaku will just get him back from the past.

Unlock Sound Test Event

Beat the game in normal mode.