Where to get the keys to Eclipse in Silent Hill

Essentially, you just have to get lucky and pick up the liquid. I did the exact same thing, inspecting the liquid and simply moving on - and there's no reason to believe that anyone else would do differently if uninformed.

The same thing happens in Final Fantasy XII, when you have to know not to open certain treasure chests early in the game, with no clues whatsoever, in order to get the most powerful final weapon. This is just another one of those missible things that you have to catch, but with no clues as to how.

3 is a direct sequel to 1. Beyond that, there are some less obvious connections and thematic bonds but none of them can be said to be beyond-a-doubt connected. There is a very strong argument for 0rigin being in continuity with 1 and 3, a weaker one for 2 and 4, and beyond that who knows...this is a pretty loaded question because it's a major point of contention in the fanbase. Like a lot of things in Silent Hill, nothing's ever spelled out clearly.