The Sphinx room is another room that is straight forward. However, this walkthrough will help you to obtain S rank by helping to know exactly where to look.
1. First pick up the hammer.
2. Pick up an airplane.
3. Place the airplane into the slot on the right side of wall to obtain a fossil piece.
4. Use the hammer to break the part underneath the sphinx face. Place the fossil piece inside.
5. Use the hammer to break the floor with the mark to obtain a piece of eye.
6. Grab a piece of eye from the sphinx.
Combine the two eye pieces together. Place it back into the sphinx eye socket.
7. Check the pyramid to start the puzzle. Note the code on the floor showing 1324 Use that to solve the pyramid puzzle.
9. After solving the puzzle, you will see that you will have to break the sphinx. Now use the hammer. You will have to strike twice.
8. After the sphinx is broken, you can now grab an earth from the pyramid. Place it into the center.
10. Escape from the room!