Playing as Phillip:
Use your knife on the panel with the red button to pry it open and reveal a crack. Use the crack to open the door but the crack will break off after opening the door slightly. Use your knife on the door to give it to Joanna.
Playing as Joanna:
Pick up the EYE that has fallen from the cracked statue head. A strange message will appear and another eye will drop to the floor. Pick up that EYE and put in the statue on the right. Again a strange message and another eye on the ground. Walk to the right to leave the cave. The statue head here has a green eye. Use the knife on the green eye to pry it off. It’s a GREEN SPHERE.
Insert the white eye into the stone head and another one pops out. Pick up the EYE. On the left are some rocks. Pick up a ROCK from the ground and enter the cave again. Use the eye in the stone head on the left and the door will open again. Look into the bowl on the left to find a red sphere but you can’t take it because of the spider.
Use the rock on the bowl to smash the spider and take the RED SHPERE out. On the wall, above the puzzle is a plate. Use the knife on it to pry it off and when you look at the plate on the floor, there’s a riddle on it. Leave the plate and look at the puzzle on the door. Take the YELLOW SPHERE from the puzzle. Now what did the plate say?
You traveled from the forest to the south west. That means the forest (=green) is north east. Below is blood (=red) and the rising sun (=yellow) is the last thing. So put the green in the upper right, the red in the bottom middle and the yellow in the right one next to the grid (far east). Another door will open so go through. Here you’ll find Goldbeard.
Playing as Phillip:
While Joanna distracts the giant, take a PEA from the plate and walk to the right. Put the pea in the bowl with poisonous spider blood and walk back to the left. Put the pea back on the plate and watch the giant finish his dinner.
Game source: A copy of the game was found here on the internet.