It is not that difficult, why not giving it a try?
And if you are really stuck...
Spoiler
Scratch on the walls
Look at crack in upper left of the screen, the rock
is softer here, but a tool would come in handy...
Go left, try to grab pick axe
Talk to knight : Why...
Go back, try to reach glinting spot (second boulder from left),
there is a yellow spot
Go left, ask for ladder
Go back, use ladder and scratch at yellow spot
Take gold
Go left, throw gold to the left
Save! You have only little time left
Take pick axe, go right
Use pick axe on dark area at the right of the cave and make a hole in the wall
Put back pick axe
Try to go through hole ("use" hole), it is too high
Take ladder and move it to hole
Get out ("use" hole)
Take rock and place it on the hole again, from outside
Go right, and right again, you can't go into the castle
Go back, drink water
Climb wall, try to enter through windows. You can't go in yet.
Climb down, go left again
Speak to left hole in hull
Go inside, talk to George, exhaust all dialogs
Get anchor
Open grate and go down, get out again
Get potato from barrel
Get spice from behind water pot
Take mint from table (red spot at the right corner)
Take cookbook from shelf
Get out, go to castle and climb wall again
Use anchor as grappling hook on upper window
Enter, search room
Go out, climb down, left, enter ship
Put potato in water, wait until it is cooked and take it
Go left until you see the sheep and hog
Try to get hog with book, no chance
Go back
The cyclops catches you
Give book to hog
Get spell book
Give mint to sheep
Take straw (and eat it)
Talk to cyclops
Give potato to cyclops
Read book and wait until you become a sheep
Wait until night (walk around)
Go to ship and enter, talk to George
Talk again to George, become a frog
Go to castle entrance
Enter door to the left, look around, look at books
Get out, sheep and hogs will follow you
Go to far left screen and through the gate in the fence