Super Mario Zero is a complete redesign of the original Super Mario Bros. featuring a full 8 worlds. It starts off challenging but quickly becomes unfair. While it is definitely possible to complete without save states (I did it twice), I recommended at least practicing the harder parts with states to reduce frustration. This hack is certainly meant for a special breed of masochist.

Notes:
-Backwards jumps to accelerate you faster may be needed in parts.
-Jumping off an enemy while you are both ascending will give you a higher bounce.
-If you get stuck look up my playthrough on Youtube