It was put together well, even though it made no sense.
I think the guy who made this animation probably has an alternate, X-rated, version of the ending between Master Chief and Samus somewhere on his harddrive....

Well, if you read his comments he/she actually says that it is not Master Chief, but some other Spartan that is alluded to somewhere. It's like really really geeky fanfic...but the animation is awesome. I'm curious how its done, because if you read the writing he/she says the methods that he/she uses would be laughed at by professional animators.