can someone help me eddit changed special edition save files? (sorry for bad grammar english is my second lenguege)

Basically, I've done every other thing I possibly could to get a diff ending. I've watched a full game playthrough and have really been hoping that Its just been because I missed ONE interaction with Puro. (No I don't mean waking him up) And yes, I'm very sure that I've been playing on normal. Signified by the four tentacles I get on the squid dog fight. Do I have to restart? Or can I just go back to the start of the water area?...

ANYTHING BUT PURO!

ok i do not own it and i have ben watching it for 2 years it caught my eye and today i got very curios and i was wondering "huh this game looks like it has a story that is told good like a book." now i am not a member nor a huge fan let alone a fan i do know it has a good story jucie as half life's story but less complex i see the ups and downs hints my qustion do i make the purchase or not im not sure can someone help me decide?...

it will bring me to the main title but i cant do anything else