Last Ninja Solve
This is not completely mine but I have added and corrected some things.  The
Doctor.
Some hints for the game:
*Very important : save the game before you fight or cross the rivers!!!
(It's like a little cheat, you can restart after you lost your life or power) 
The Doctor's Hint on Fighting:  I am not good at things like this so I developed
the following.  Enter a screen where there is to be combat.  Get in a telling
blow without getting hurt and then back out.  Save the game and then repeat
until you kill the guy.  If it is a screen where the guy revives after you leave
(yes, it happens alot) don't save it here but wait for a save screen.  I did it
this way and won -- killed the master without doing this but I had little of my
three lives left.
 
Level 1: The Wastelands.  Get all the flashing objects. You don't have to kill
all the enemies. However, you must pick things up in order.  You don't have to
cross the rivers in this level, you will endup circling around. After you get
the sword, numchucks (chained sticks on a dead body), smoke bomb, key, and a
little bag. Then you go to the place where you found the smoke bomb. The color
of the river is red (probably lava), jump to the upper right corner (you will be
at another screen).   Then, you will find the apple (extra life, if you still
have 3 lifes, you will get a total of 4 lifes. Also if you have low power
status, press contrl-H to kill yourself (get the apple first), then you can get
another apple)..Later on, you will find the ninja star (these is limited, save
them)..When you get to the screen where you see a pink dragon, the only way to
pass this screen is to throw one of your smoke bomb (you must throw the bomb to
front of the dragon), then the dragon will fall to sleep, walk over and you have
passed the first level.
Level 2: The Wilderness.  You have more things to get, I don't think that you
can enter the house in the first screen of the 2nd level. Get the claw in that
screen (it's very small, in front of the stone lion (right side)...) Later on
you will find apples again. When you reach the screen with a tall cliff, you
have to climb up the cliffs (with the claw, of course). When you get to the
screen with a brick wall, climb down backward. don't forget to hold the claw..
(Do it on the right  side of the wall, the white part on the bottom of the wall
is ok..).  Cross the river on the next screen.  In this area you find the glove
and ninja magic which makes you flash.  Get the glove and then the magic.  Hurry
to recross the river, go up and cross the river again.  Hurry, fighting if you
have to, and find the two stone dragons, the second one will fire at you but if
you have ninja magic still working fast enough you can get by.  You have passed
the 2nd level..
Level 3: The Gardens.  You will find another apple tree...get it..more
life..yea! First you have to get a golden necklace on the budda's neck (where
you have to cross the river through the rocks on the river)..this river has a
blue dragon, don't pay any attention to it, it won't fire at you..After you get
the thing, go back. Find the flower. Pick up with flower with your glove. Keep
going ahead. when you see a small river (with no rocks), jump over the river (it
took me few times to do so) Later on, you will find a golden Budda Statue, kneel
in front of it with the golden necklace and you have passed level 3.
Level 4: The Dungeon.  This is the fun part with nice graphics, don't even think
about fighting the gaint spider, or killing the ghosts or mice (you don't have
to kill them anyway).   (The easiest way to kill the skeletons is to kick them
once) Again, find the apple and a rope. Walk around until you find a chamber
with 2 rows of steel rings on the wall (like a ladder), kill the enemy and climb
up with the rope.
Level 5: The Palace.  Get the apple again (This is the last one).  On the same
screen, use the key to enter the door.  You then want to go left.  In this
screen, you can get by the guard without fighting and he will commit hari kari.
Sort of neat.  You will then be in a room with a giant statue.  Save it here.
Get next to the statue and slowy (clinging as closely as possible to the statue
and facing up - toward the statue) work you way slowly around the statue.  The
sword will eject and you will be safe.  (This part provided by Ed "Apple Guru
Moore" - TSEMM@ALASKA)
This next part is crucial in my opinion.  Proceed forward to the next screen and
almost (not quite) kill the guy there.  Then go back to the statue screen and go
up.  (Note if you save the game on the screen with the statue, you will have to
get by the statue again).  In the upper screen, kill the guard and get the Ninja
magic.  This is short lived and you have to move quickly.  Return to the screen
where you almost killed the guy, finish him off and exit using the read stairs.
If you do not have sufficient magic, you will die on the stairs.
Level 6: The Inner Sanctum:  Warning:  there are no more apples.  This level
starts as a hallway in which there are four rooms.  The fourth contains poison
(needed later) and the third the passage to continue.  Each room has a guard
outside and there is one in the third room.  Trying to figure it out, I found
that the level is a wrap around.  Therefore the best way to go on (with the
least amount of fighting) is to exit up the screen instead of down.  This puts
you in front of the fourth door.  Kill the guard, then go get the poison.  Come
back and kill the guard again, go to the third room (exit up), kill the guard,
enter the room and kill the guard.  The exit the door way up and hold the
flower.  Walk to the last big vase at the end of the room.  The flower will be
put in the vase causing a secret passage to be revealed.  SAVE THE GAME.  The
next part takes practice.  Hold the poison bottle and carry no weapon.  In the
next room, you see a grey dog, walk slowly and when the dog wakes up, throw the
posion bottle.  You must throw it right in front of the dog. Then you enter
another room with a giant statue with a big arrow . In the upper side of the
corridor where you enter, there is some red (blood?) on the carpet.  This is
concealing some ninja magic.  Get it and you are by.  Don't save it now, wait
for the next screen.  There is one guy to kill and then the master.  He is tough
(wearing armour) but beatable.  Then you are in the last screen; save your game.
Put away any weapon.  There are two squares - you must jump and land inside the
smaller.  Then take the scroll and watch the ending.