That was utter ♥♥♥♥. Utter. ♥♥♥♥.
That's got to be the worst ending I've ever seen to a series, ever. Mirai Nikki was a great series, enthralling, full of suspenseful twists and turns, but then suddenly, the last "arc" comes around and goes full-retard on us. Yes, the part about Yuno being a time-traveler was rather ingenious, but everything else...
Agh. Anyway, I feel like I won't get my point across without bringing up the TIME-SPACE BREAKING HAMMER, because that was the most blatantly ridiculous part, but you guys won't get it since the anime decided to leave it out for some reason (I'm guessing they found it as utterly stupid as I did and wanted to save face somehow), so do yourselves a favor and read the last chapter of the manga.
Then you'll understand.