ok i just finish the game last night so here are the ways!
first in the game go to the spider cave,slash all the enemy that you see it might contain potion that you need later and equipments then there is a elevator i think that way to the queen spider now for easy kill go to its back first then go slashing its head to the finish! watch out in your health meter then one you made in you will receive an item then go back to the village for long talk then go straight to the left there is an archer that will atempt to kill you go fight first then he will give to you the bow then once you reach the castle shoot the circle above to open the gate and said! fight as much as you can to get items then go to the top of the castle and you will encounter the bad robot! it just easy to kill just slash its body and that is! then one you finish it go to the old man and a long talk hehehe! then go back in the cave under and use the earth attack to crush the crack ground! NOTE! once you enter the cave remember the path that you walk its the same path that you must take! then again! check for items once you are in the bottom there you will see the giant that is prison for years i think! then accept his wish to fight you! dont worry it is easy then once is done he will give the hammer once you get it explore the cave for more until you fight the flame monster! once you defeat him you will receive the flame attack then you can use it in ice blocks hehe then go to the left again where you are in a snow village they ask for your help once its done go to the left and use the earth attack to crush the floor in there you will fight the ice monster or minitor! he will drop the ice attack once its done go to the surface where you see the old woman takl to him and she will give to you the ninja suit! go straight to the left and you will see a water fall use the ice attack to frezze the fall then quickly climb! once its done there is a teleporter that will bring to you in neo-tokyo! then go straight! once you encounter ninja robot they will give to you the super jump once you receive go to the top of the last building to crush the generator to the ground once you made it find the professor that has been prison for weeks then wait i forgot! sorry find also here the wind attack i think its the boss up to the tower! YEAH! then once its done talk to the professor then step to the platform in front of him then you will go to the aku city! this is the difficult stage just be careful! just go straight until you will encounter a croc that will explain what the amulet is! once its done go straight to the right until you reach some cars passing by just jump into it until to the top once its finish just keep jumping until you reach the last save point! save first! once its done go to the left and kill aku! whee! any question? just reply this! hehe!