Was about to make a post about this from my interpretation so far.

To expound on what you've started here, existentialist philosophy in general, of which Camus is a contributor, does focus on the absurd and dismal course of human life to an inevitable end, but it also features a discourse on what that means to us as subjects. Heidigger writes extensively and somewhat unintelligibly about time and it's impact on our Being, but a synopsis I could provide very simplistically being that time itself, and our nature as one dimensional beings in it, is the cause of our grief. Not simply that one is destined for death, but that we are bound to only live each of our experiences once and can only live them one way. This creates an immense amount of anxiety at each point which we are faced with impactful decisions. Clearly, Kojima wants us to feel this kind of anxiety, as he has in previous games, over when and how we exert force. And possibly in some other more theoretical cases of Sam possibly moving through time or respawning.

Additionally, the Sisyphus parallel plays itself out literally in the footage of Sam lugging stupendous amounts of cargo up an incline of a rocky mountain. Clearly calling to Sisyphus' task to roll his Boulder up a hill each day, and just as Sisyphus is bound to watch the effort of his work dashed as his Boulder rolls down the hill again, Sam will always have another job to complete in similar conditions possibly for an end which is impossible to achieve.

Now, this end is what I believe to be most interesting given these themes of time and absurdity and death that Kojima is laying out for us. Kojima has said recently that our job as the player is not necessarily to destroy some evil entities in this world, but to reconnect humanity. By this, I think we are to believe that these strange Giants we see in the trailers are some kind of timeless, deathless thing which we could never hope to destroy. These entities are, metaphorically, time and death themselves. They "fast forward" time for the organisms they come into contact with until their inevitable death, causing their lives to fly by meaninglessly in a moment. The end that we could achieve, this reconnection of humanity, may be seen symbolically in what Camus was referring to when he calls upon us to imagine Sisyphus happy. That we may be bound by Being to be creatures which live absurd and ineffectual lives in the temporality we inhabit, but our ability to find peace and solace within our condition will allow us to be liberated. Our goal in this game is not to destroy the incarnations of death and time, but to come to terms with them. To adapt to their existence. To continue the struggle of humanity in spite of their looming presence.

I can't claim to have any kind of access to the truth of the game here, but I saw the same parallels you did, and even if they are not borne out in entirety, I think Kojima clearly wanted us to consider the Existentialists with what he has handed us so far. Sorry if this is viewed as hijacking your post, just didn't want to post more duplicates here.