I have completed Dizzy 1 ages ago, but I was sure at the time I hadn't done everything possible.
Well, this time around I have found the secret area with the pickaxe. The trouble is, in order to get there I have to use up the dry ice which seems to mean I can't get the amulet and defeat Zaks.
Is it possible to do both? And what is the point of these secret items (crystal, dagger etc.) anyway?