HumanCaterpillar

(I'm not sure how to hide spoilers on mobile but this entire post is just spoilers so beware) Alright, I haven't read any of your other theories so i don't know how redundant I'm being right now and o haven't proofread this either but here you go, my dudes:

"Inside" takes place hundreds of years in the future, when a new species of human, aptly dubbed "posthumans" exist. These posthumans are capable of superhuman, seemingly supernatural feats, and hardly live past puberty. Nobody knows why, but all of their hearts just mysteriously stop beating before they reach adulthood. An organization is adopting these kids and helping them learn to control their powers, as well as keeping the outside world safe from the posthumans. This brings us to our protagonist, who I shall henceforth refer to as Red due to his red shirt. Red is being kept at one of the organizations many facilities as they attempt to get to the source of his power, which seems to be the ability to control animals (all animals in the game follow Red, which is why I believe he's unconsciously controlling them and making them follow him). The scientist believe this to be the most powerful of posthuman powers as, with a little help from certain machines that they have on hand, kids with this ability can also control people. Actual people are rather difficult to control, but dead bodies are a piece of cake to control, which is why they have various dead bodies scattered throughout the facility, there used to test the children's powers. The part with the zombies all lined up and walking is just another kid with the same ability being tested. The scientist take extra care of these kids, as they're the most valuable, by infecting remote-controlled nano-machines into their bodies which help their hearts pump blood, all in an attempt to keep them living as long as possible. Red eventually decides that he doesn't like being locked up anymore and decides to breakout, with the various guards attempting to stop him and keep the outside world safe from his potentially dangerous abilities. Eventually, Red comes across another kid, who has the ability to breathe underwater, who was being experimented on and eventually, in a fit of rage, flooded a portion of the facility, inadvertently trapping themselves, as they couldn't find any other way to escape. The scientists then created a submersible thing so that they could navigate the flooded labs and retrieve the water child.

While they were down there, they discovered that the organization has been essentially saving and uploading the kid's powers to a machine with the ability to give anybody any of the powers that have been uploaded to it. This machine was lost and abandoned during the flood but was found by the water child, who uses it to amplify Red's powers as well as give Red the ability to breathe underwater. The scientists have also been experimenting with the "blob effect", a strange occurrence that sometimes happens when two or more posthumans get with an inch of eachother, which essentially merges them together into s big blob. The scientist are curious as to how this affects their powers, and are experimenting on them to find out. Eventually, Red is absorbed by the blob that was being experimented on, and becomes part of a mindless monstrous glob of flesh and skin. As for the second ending, I think the orbs that need to be destroyed are simply a security measure, preventing the door beneath the cornfield from being opened, and once Red destroys all of them, he can open the door to the "heart" of the facility. By unplugging the cords, he powers down the whole place, and inadvertently powers down the nano-machines keeping him alive, killing him.