In answer to the question of where the last 
crystal was in the spider cave, their is a second
water pool that dosn't have dark eco in it. So 
that is the fifth crystal. Also the 7th power cell
in the volcano crater is that box on the rocks by 
the coal mine carts however after powering up I 
still can not shoot it, but I here it has been 
done.

by unknown


The 5th crystal in Spider Cave:
 
The crystals seem easy to find, but they get harder
as you destroy more. The 1st you destroy should be 
the one in the first room, with the gnawing lurkers.
The 2nd near a Dark Eco pool between the gnawing 
lurker room and the lurker mine. The 3rd is on a 
ledge between the dark cave and the gnawubg lurker 
room. The 4th is in a water pool (not Dark Eco!) in
the dark cave. Also finaly the 5th is in a water 
pool by dark cave. when you enter the room with a 
Dark Eco pool that you have to hop accross, on your
way to dark cave, instead of going left, go right. 
You have to get accross the dark Eco pool by 
running at it then pressing (and holding) L1 then 
before you get to the edge, jump. You should perform
a Roll Jump to the other side. then you dive down 
(into the water) and hit the crystal before Roll 
Jumping back again.

Submitted by slipknotsgoat at hotmail.com