it certainly looks like it, but only if we assume that the very first scene shows the futureAlso, after rewatching the beginning of episode one, I'm thinking Yuki will sacrifice himself in the end.
but then the clone-theory wouldn't make *that* much sense, where did the clone come from (ok that deus-guy said something about some disorder in the causality-continuum) and why would she kill her other-self with such madness?
but what happens if we assume it shows the "past"?
what if we assume the game has already been played
and Yuno won it because Yuki sacrificed himself at the end
Yuno would've become a God..the "God of Spacetime" as Deus said....
now what would someone like *her* probably do, to be at his side again
go back in time, kill her old-self (Haruhi-movie style) and take up her place!
then try to protect Yuki no matter what or maybe just to spend some time with him, since they couldn't do so before.
maybe thats why Yuno's diary is already saying "happy end" because from the beginning her goal has always been nothing else but to come together with him (again)...to be honest I never got why it stopped recording his future after that day.
and alot of her statements become more suspicious imho
for example the big-wheel scene in ep3... Yuki doesn't get why she is following him around and he can't believe that one conversation has turned her into such a stalker.
and Yuno says "its a secret"
so probably, something has happened during the first game which made them fall in love with each other.. and of course she doesn't want to tell him that.
god I wish something similiar to this will happen/happened
Yuno is already one of my favorites characters, but this would probably place her on top of everyone else in my list. Crazy Stalkerm gotta love them, especially if they are female