The All Items Definition has been confirmed the Secret Items you get for doing these specific actions on certain Series of levels:

Bonus target (10,000) Reveal the exit and walk over it without defeating any enemies. Stages 6, 8, 14, 16, 22, 24, 30, 32, 38, 40, 46, 48 Game (20,000,000) (Replaces Dezeniman) Destroy every soft block without defeating any enemies. Stages 5, 13, 21, 29, 37, 45 Golden Bomberman (500,000) (Replaces Famicom) Create 248 chain reactions with your bombs (You can use remote Bombs). Stages 2, 10, 18, 26, 34, 42, 50 Nakamoto-san (10,000,000) Destroy Every Enemy and blow up 16 soft blocks. Stages 3, 11, 19, 27, 35, 43 Rooey (20,000) (Replaces Goddess mask) Defeat every enemy and circle all around the outer wall of the level. Stages 1, 7, 9, 15, 17, 23, 25, 31, 33, 39, 41, 47, 4 Yo-Yo (30,000) (Replaces Cola) Circle all around the outer wall of the level while making sure not to defeat any enemies. Stages 4, 12, 20, 28, 36, 44

A Run Must Collect all 6 of these Secret Items to meet the requirement for "All Items"