I love this game.
I reached Zone 4B using the continue cheat.
Finally killed the boss duo at the end of Zone 4. I didn't really understand the pattern, I just got lucky.
I have reached ZONE.5 and I'm having trouble with the spear and shield guy in the beginning. I think he only takes two hits (even on the shield) with the fully powered up axe.
In ZONE.5, the small platforms with axe throwers are difficult. I can get through those platforms by spamming the axe attack, parrying the axes and attacking the throwers.