No - you can play the game without them. Earlier German versions had no pyramids in Act 3 - was playable. There is one part, where you need to overcome a lava gap if you wish to get the joker BF key. This can be done with the Ethereal Magic spells => "swap places" or "Teleport" - available for free if you kill a certain mage or by buying these from Serrick.
Kiya
I agree though with this => life is easier in Act 3 with these pyramids.
