Spoilers..




STEM locked Grey away, giving him a dream state that amounts to a Matrix-like false reality that he could accept so that STEM could retain control unchallenged. They took the "it was all a dream" ending and flipped it brilliantly if you ask me.

So STEM is controlling Grey's body, but Grey is still there, somewhere, in a dream state.

I'm curious what's not to love about this.

The lone critique I have is that the revelation comes without motivation. I would have liked a bit more exposition, particularly since the director made this film with zero plans on a sequel.

Apparently thats now in the works, but he said not to expect a sequel before it even hot theaters.