Help with Xak II

The four treasure chests are not meant to be opened. There's no way to get there.

You'll have to slay a boss for that. Iirc Ebu Fyl will give you the Brass Key.
You'll find her on the map 04_Xak_2_-_De_Mijn.png in the left bottom corner.

I wish I remembered.
The last time I booted the game was to make the maps. If it's not in the maps, I do not remember. Other people might.

crystal mines: you need to enter the first door when going to the left in the crystal valley. If you are warped when you go up through the door, that is a copy protection. The room you get warped to in that case is a small room with four chests. Normally you are not able to get in that room unless you are using the debug mode.

On a correctly working disk(image) you can just walk through the door without getting warped. In the maze you should be able to get the brass key. Iirc it is somewhere in the upper right corner on the floor with the blue giants that come charging at you with their fists. You need to warp around there by touching invisible walls (other warps are correct). Once you have the brass key you can use it to operate the elevator to get to the area boss.

If I remember correctly there is a doorway just to the right of the warp so you need to enter a door. The doorway isnt visible on the map since you exit it on the north end of a wall. If you have trouble seeing stuff press the caps to see through walls.