12. The banded blue lights look familiar...
The MGS: Ground Zeroes trailer featured a series of orange, banded lights at key moments, marked by a distinct audio signature - the potential significance of which I expanded in the Swoosh code conspiracy. Sorry about the title.
The Phantom Pain features blue, horizontal, banded lights at key moments, usually when direct light is being shone toward the camera, or rather, into Big Boss' eyes. Could it be that the light represents an intrusion of reality, as someone peers a light into Big Boss' eyes as he lies in a coma? Or are they just an elaborate visual effect, like JJ Abrams trademark lens flare.
In the case of Ground Zeroes, I'm certain the orange lights are more significant, and this likely follows for The Phantom Pain. At the very end of the trailer, when Big Boss' face is revealed and a spotlight is shone into his eyes, the shimmering audio effect is nigh-on identical to that which plays during the orange bands in MGS: Ground Zeroes.
13. Psycho Mantis as a child... on the ground floor?
A child-like figure appears in a lift, wearing a gas mask that looks similar to that worn by Psycho Mantis. Is this Psycho Mantis as a child? *May-be*, but Psycho Mantis is born circa 1970 in MGS lore, and if this is 1972, he'd be only two.
The flames, however, are indicative of Psycho Mantis, who uses his telekinetic powers to burn down the village he lived in as a child. He receives severe burns across his body, and especially his face, due to this release of psychic energy.
It's seem more likely that all the trailer scenes featuring flames are induced using Psycho Mantis' powers - or perhaps even by The Sorrow from MGS3, who has similar abilities and better fits the assumed time frame.
A number of flaming, mystery characters make appearances during the trailer, with their faces obscured. Speculation links them to Boss/Raiden/Raikov, Snake in his Peace Walker sneaking suit, Volgin and The Sorrow (this is much less clear) on a flaming horse. If you over expose each image to reveal more detail, you can see that they're all wearing a gas mask, or something very similar - suggesting they're all apparitions of the same origin.
Is Psycho Mantis/The Sorrow probing Big Boss while he's in a coma? Psycho Mantis doesn't die until 2005 in MGS lore (during the events of Shadow Moses/MGS on PSone), and Big Boss enter his 15-year-coma after the Zanzibar Land disturbance in 1997 (after he's badly burnt by his 'son' Solid Snake). The timeline fits, but this is highly speculative.
It's also worth noting that the lift is in on the ground floor - a link to Ground Zeroes?
14. The patients are being systematically murdered - but do they all look the same?
The hospital patients are picked off one-by-one, but share similar characteristics: shaven-headed, relatively lean, in their mid/late 20s. It wouldn't be too great a leap to suggest they all look like soldiers. We'd be surprised if they were IT technicians, anyway.
The first few to get shot look identical, but other patients have slightly different hair, and facial hair - one has a goatee/chin strap (in the crowd scene), another dense stubble. However, broadly they look similar. Could they be clones? It could be that someone is testing the basis of the Les Enfants Terrible project (although Snake/Liquid are born as children via a surrogate birth, not emerging fully grown, so this is a stretch).
During his 15 year coma (1997-ish to 2010s, before his body is recovered by Eva), Big Boss' genome is used to create Next-Generation Special Forces via gene therapy, so this *could* be a link. One patient has a bandaged left eye, evoking similarities to Big Boss (although he has a missing right eye).
It's entirely possible that they're all real people, and might even be grown up soldiers, as alluded to by Chico's appearance in Ground Zeroes.
Pushing the theory to extremes, are the patients an extension of Big Boss psyche during a coma? Is someone trying to wipe out strands of his personality/memories by executing 'clones' of him? If so, it'd be interesting that the bandaged patient is the one who always survives - as if hiding his identity (via the face bandages) is the only way to survive?
It's a big leap of faith, but fun to consider, at least.
15. The bandaged man drags you under the bed... but no one sees him
The bandaged man is in every scene with Big Boss. That's likely no co-incidence. He's holding his arm as you awake to survey your prosthetic, and 'drags' you under the bed when the guard appears. When you're in the packed corridor and peppered with gunfire, everyone gets shot apart from Big Boss - who turns his head to see... the bandaged man hiding safely in a side corridor.
Are Big Boss and bandaged man one and the same person - like Edward Norton/Brad Pitt in Fight Club? It's possible that Big Boss has split his psyche during his coma, with one part retaining the 'soldier' status. The bandaged man is certainly the dominant partner, always leading the way, or helping you out.