A, Up, Down, Left, Right, Start - Extra 5 Lives (available only before the stage screen)
B, Up, Up, Up, Right, Start - Level 5 (available only before the stage screen)
Select, B, B, B, Left, Start - Level 9 (available only before the stage screen)
Up, Up, B, A, B, A, Start - Do not clear powerups and items after death (useful only after death)
Down, Down, Up, Up, Start - Water can't dodge you back (available at any splash screen, need to be reentered any time after death)
Left, Left, Right, Left, A, Start - Level 13, Enables gravity (available only before the stage screen)
Right, A, B, A, B, Start - Junior bee option, twice the weapon power, and defends from the instant death once (available at any splash screen, can be reentered after death)
http://cah4e3.shedevr.org.ru/cheatsbase.php#166 (http://cah4e3.shedevr.org.ru/cheatsbase.php#166)