Blow your horn to call your man. Listen to their plans. Use Little John's plan. Wear the fire ring.
Go to Pub. Talk to man until he let you into the cellar. Use the secret passage to reach St. Mary. Take the passage to the north to the maze. Walk to exit as fast as possible. Open the door (you should hear the horn blowing) and save Marian.
At willow. Use the emerald heart to heal Marian. She will tell you the password.
Blow your horn. Use Tuck's plan and ambush the treasure train. This get you enough ransom to save King Richard.
Transform into tree in any grove to evade the enemies.
Go to overlook. Walk to knight. Show him the password. Talk to him. When he swing his sword, shoot him. He is a false knight.
Go to swamp. Wear the water ring. Talk to water spirit. They'll bring you a boat. Use boat. Follow the water spirit to go through the fog.
At the tower where the knight is held. Get the ivy (this let you exit the boat). Use the hand language to show GORT (the druid name for ivy). This make the ivy grows so that you can climb up. Climb up to the window and talk to knight. Show him the password. Climb down carefully, watch out for falling stones.
Once you have climbed down and reached the boat, everything will be automatic. So, sit back and watch the end game. If you have gain enough support from the folks, you'll win the game or else that's the end of you.
That's it. You have finished the game!
You might want to replay the game making wrongs move and see what will happen at the end.