Quake - Termination Central (E3M1) + The Vault of Zin (E3M2)

I am now at the beginning of Episode 3, The Netherworld, where most of the levels that are past the first one are filled with lava, the deadliest hazardous environment in the game, obviously. Here's one of the most unfair thing that I notice with this game. Enemies aren't affected by environmental hazards at all, meaning that they can have their ways with you without worrying about getting burned.