I believe everyone will be judged accordingly, b/c I believe God is just and fair. I believe God testifies of himself and salvation even in his creation. Christ died for them, as much as he did us. Scripture also tells us in the most well known verse John 3:16 that God doesn't want anyone to perish. There is no one that he does not want to be saved, He does not want to see anyone reject His salvation. The requirement for salvation has always been faith. The object of one's faith for salvation has always been God, and the way of salvation made through Christ. I tend to equate people in the depths of the jungle with the OT believers. God's requirement of what must be believed is based on the amount of revelation He has given mankind up to that time. God knows exactly how much has been revealed to each individual. Someone once told me there was only about 5% of the world that had not heard of Jesus Christ, so 95% of the world has had Jesus Christ revealed to them and while the other 5% has not, they have had God revealed to them, through their heart and creation. I believe people have an inner awareness not only of God's existence but of their imperfection and need to be made right. They may not know the terminology or names for this, but they still have the ability to call out to the "creator of creation" (although they may not know his name - not the creation but the creator) and ask forgiveness for what they know they have done wrong.
“In the past God spoke to our forefathers through the prophets at many times and in various ways, but in these last days he has spoken to us by his Son, whom he appointed heir of all things, and through whom he made the universe” (Hebrews 1:1-2)
I have no doubt God works the same way in the depths of the jungle. He brings missionaries, prophecies, and calls out to people through his creation and in their hearts.