Standing your ground will see the cobra headed missile snaking its way towards you, before severely damaging your health on impact. If things get a little tough then you could always jump in the water for cover. Unfortunately the creatures will gather around the pool and await your return, or perhaps they have just congregated to watch the fun, as you fend off the school of Piranhas that have surrounded you, with their razor teeth stripping your flesh from your bones. The buxom, bikini clad beasts can run faster than a cheetah and will render themselves invisible when under attack, only to reappear right beside you when you are least expecting them. I will once again refrain from spoiling the game by describing the Bosses that you will face at certain points during the proceedings, but it is suffice to say that the Cyberdemons in DooM are kittens by comparison.
Slow progress is the order of the day.
I recall blasting a hole in a wall to reveal a room full of goodies. Overjoyed, I ran towards my haul not noticing a well disguised pit, my feet hit fresh air and I plummeted down the trap. I quickly pressed my hover button, which slowed down my fall, and glided downwards for what seemed like an age. When my feet hit the ground I was ambushed by a tribe of Mummies and Mutant Flies. I escaped with my life, but only just.