I'm going to start off by linking some of the images here:
If you click left, you get

An imgur sequence jwg72, leading to an apparent riddle and tentacle monster

If you click back,

Back is not an option

If you click forward, you get

This riddle

If you click right, you get

a bunch of weird voices in a cave

My first thought is

go right, since one of the voices is talking about a key and we might be able to use it; I'm not appreciating having to face off against any of the creatures of the deep behind doors 1 and 2....

I'm going to start off by linking some of the images here:
If you click left, you get

An imgur sequence jwg72, leading to an apparent riddle and tentacle monster. Since we know the answer is TAD_, we have to find the number that is not mentioned. From below, it's not 9; further, 50 is written on the right wall. From the prequel puzzle, the address 318 is featured; further there are 2 twins (the word two is written in the prequel). The URL for left door contains 7 and 2; the URL for right door contains 6. This leaves 4, so is the code for the left door TAD4?

If you click back,

Back is not an option

If you click forward, you get

This riddle

If you click right, you get

a bunch of weird voices in a cave

My first thought is

go right, since one of the voices is talking about a key and we might be able to use it; I'm not appreciating having to face off against any of the creatures of the deep behind doors 1 and 2....