Quick question for those who finished (please no spoilers!)

I've been enjoying this game greatly, and had some mind blowing revelations, but will it be apparent when I solve the mystery and "beat" the game?

No it won't. There's a prompt later that lets you quit the room but that's it. You leave when you feel like you are satisfied.

Once the prompt turns up, you can click that and there will be an ending of sorts and a credit sequence. I'm not sure what triggers the prompt to appear; for me, it popped up when I had a fairly good grasp on the story.

I see, thanks!

If it helps, I definitely felt like I'd finished the game by the point the credits rolled.

After the credit sequence you can go back in and continue your searches for any new videos where you left off. i.e. It doesn't force a new game.