Hint :
Chamber of the Kings:
There are two crowns here, one at the bottom left, one at the top right. Don't touch the bottom left one, it's a trap. Get the top right one which opens a door on the right bottom side.

Room of Screaming Skulls:
In here is a single altar and four skulls, one in each corner. All ask for the same thing, an amulet. Give it to the bottom left one to open a door at the top of the screen. In there you find a stone, the Eye of the Beholder on a fire altar. Don't touch it yet. Here's how to get it. Earlier you will have found a poison potion on an altar on the far right of the map. Put it on another altar (I'll tell you which one in a moment!) to change it into a fire protection potion to get the Eye of the Beholder. With this stone, go straight down, right, right, down, left, left. There is another altar here with no name to it, symbolised by a centralised stone, half black, half white. Put the Eye of the Beholder on it and it will change to a crystal. This is also the altar to put the potion on.

The Chasm:
To pass the chasm, you need the second candle. To light it, place it on the fire stone found past the third guardian. Then put it on the altar with the other candle to open a chest at the top of the screen and get a chalice and a crystal. Then cross the chasm on the wood - remember to pick up the wood because the next room has a chasm that opens later.

Lozenge Shaped Crystals:
Push these into the mouths of the guardians, then they close their wings so you can pass. The colour of the crystals matches the colour of the eyes of the guardians.

Big Gem Stones:
These round gems must be put on doors - not the bolted doors, the ones like a pole with N,S,E,W on them. This shuts the doors.

The Sole Potion:
Yes, that's SOLE as in feet, not SOUL! This protects you in the part of the game where you need to go along a long tunnel to get to a knight. He was buried near electricity so the potion stops you frying. In his chamber put the sword on the altar to turn it into a shield. Get it and the electricity is deactivated.