This is the 5th level (although the previous levels are very short so you reach it quickly) and i always dreaded that level because of this:

http://i.imgur.com/nlqCyxm.png

Touching the steam kills you instantly. But ever since i first played the game more than 15 years ago, what i was always doing was to jump on the first pipe, then down the platform, then up the next pipe, etc. There is little room to stand on there and i thought that this was the normal way. Make a very slight misstep and you are dead. Fall down in the water - dead again because there is no room in the ladder at the right to fully rise before you get burned by the steam (i always thought this was some sort of sick joke from the level designer).

I've beat the game many times, i do at least one playthrough per year, sometimes more. Yet i never realized that there is a way to disable those steam pipes - there is a lever in an area i somehow always ignore (in my defense, it is dark) which affects some other stuff that give you access to another area of the map where you can disable these pipes. I'm not going to spoil it, but it is about 1/3 of the map that i was ignoring all these years :-P.

I like finding new stuff when replaying games i have played before and i think this is my favorite so far :-)

Very funny!