That does not show me how to get the leftmost gems below the blue key at all. Can you upload a video showing you getting those gems and the key from the start of the level?
No, because like I've been trying to say this whole time, the gems fall into the acid before the third rock, and even if I use the "ctrl+direction" move to try grabbing the gem without going into the acid, it still kills me. The only way to get that gem is to put a third rock in the acid pool before it falls.