I don't know if this has been posted, but i was just reading up on my marathon history and noticed some interesting tieins...
In both games the player is certainly, above average, shall we say. It has been speculated that our character in marathon could perhaps be a Mjolnir Mk4 Cyborg, while in Halo the character wears a "Mjolnir" battle suit. Perhaps Mjolnir is a project inwhich the cyborgs and battle suits were created. Now in halo the character is a genetically altered super warrior, and so on, While in Marathon the character is described as always being a bit better than the other kids. In the Halo pre-quel Fall of Reach, the child who eventually becomes Master Cheif is observed as being a bit better than the other children. In the story it is revealed that only half of the genetically altered children are trained to become super soldiers, but it is not exposed what happens to the other half.
Unfortunately it would appear that the Marathon launches about 50 years before the Spartan-II project of halo. Though it is perhaps feasible that there was a "Spartan-1" Project which bread the character of Marathon, though was never trained to be a soldier. Although the question would arise as to how the Cyborgs might have been developed before the Super Warrior of Halo. In Fall of Reach the battle suits were said to have not yet been perfected for humans, which would lead to the conclusion that perhaps the cyborgs might have been developed before the genetically altered super warriors. Certainly the technology was there, less advanced suits may have been developed, and certainly a form of AI could have been derived. Perhaps though the risk of rampancy may have led to the decline of the use of the Cyborgs, though the Marathon left before the problems arose.
Certainly the stories fit togeather quite well otherwise, the marathon goes out into deep space, essentially losing contact with the rest of humanity, and then gets attacked, their message not reaching earth in time (or perhaps earth was already under attack, i can't quite remember the dates this late). In the marathon games the aliens were rather well researched, understood and whatnot, while in the halo the humans know very little, it is quite possible that these are the same aliens, though just as likely they are differant races.
So many questions, so many questions. If only Bungie would make another marathon game, we could have more answers. Though perhaps more questions :P
