Once you have the helmet go to stormeagles level get past the 2nd line of fire tanks (as x)if you have a strong weapon use it for the tanks then wall jump the tower thn slyd dwn and smash blocks with helmet and go right you should see a capsule good luck!!!!
To get haduken you need to have all the weapons, lives, armor and subtanks. To get it go back in armorred armadillo's stage then ride the cart where you will be launched in the air to reach the boss. When your the middle in the air dash and jump thir you will see a capsule at the very top on the boss 1st gate. Hope it helped.