I have to say, its been a while since I've seen an anime like this, with the amount of new animes its very hard not to end up being a cliche. So I think some credit has to be given to originality factor of this anime, although it does remind me of Eden of the East, with the whole Cellphone and Survial game etc, but I think they tried their best to keep it different.
Personally I'm not one for gore and bloody violent anime but due to the plot I just had to finish it.
The characters are all pretty average with the exception of Yuno.. probably the perfect description of a Yandere type person. She (although freakishly disturbing sometimes) but kept me entertained.
I am aware of the Manga and anime ending controversy where one had a happy ending and one doesn't, personally after seeing both I have to say that the anime ending was my perference. The manga ending seemed to far fetched and an anime like this would be much more memorable with a suspense ending.
Anyways overall, not the best movie I've ever seen and personally think too more unecessary violence and gore but then again. its just my opinion. But at the end of the day I would recommend it because I think it is quite unique.