Fun and very entertaining!

A young math genius solves a complex equation and inadvertently puts a virtual world's artificial intelligence in a position to destroy Earth.

Director Mamoru Hosoda originally made the concept while working on the Digimon movie (its poor counterpart), and wanted to revisit it and give it the animation and full story it deserved. It lives up to his wishes as Kenji accidentally solves an extremely complex code allowing a virus to infect the virtual reality world "OZ" and starts wreaking havoc on the world, both virtual and IRL.

It's up to him and Natsuki's family to bring an end to the virus and save the world.

It's definitely worth a watch, if not multiple.

Entertaining anime mash-up of Ender’s Game, War Games, and Ghost in the Shell. There’s a lot that’s familiar here: most of the characters are anime stereotypes who employ histrionics in the usual anime manner, the computerized virtual “Oz” looks a lot like the hackers’ matrix in Cowboy Bebop, and there is the expected brush with apocalypse. And yes, there’s a lot of kawaiiiii. However, everything is put together in new and interesting combinations: one would not expect, even in anime, for the rogue A.I. to appear as a malevolent Balinese deity, or the wise old grandmother to grab a samurai pike off of a display and wield it with considerable skill. There is an incredible amount of detail in the animation (there are scenes with at least ten major characters all in one shot, and all moving separately), and there are some lighting effects straight out of Makoto Shinkai. The plot is silly (in a good way), cyberpunk, and satirical all at once (it pokes fun virtual reality). All in all it’s a lot of fun.

Good movie.

Interesting! The family parts are super real feeling (like the conversations with people interupting each other, etc). The OZ parts are pretty silly, but don't detract from the story.

Not as good as I expected. Guess it just wasn't my type of movie. Wasn't terrible though

I personally loved this movie. I've seen a lot of animes before, along with a bunch of anime movies, and I can say that this was one of my favorites. Entertaining until the very end.

This is a good one. A new movie from the director of the Digimon Movie (If anyone remembers that oldie-goldie)! Summer Wars keeps the same feel to its' art and storyline with clean lines and two-toned color on top of some detailed and gorgeous background art. The story here is fun bopping along between a critical look at social media sites and the intricacies of family dynamics. A fun movie to watch and one I hope to own!
Absolute recommendation!

I LOVE LOVE LOVE this movie!! The art is really good, characters dynamic, storyline EXTREMELY interesting, the world is very exciting and well developed, and the music is FANTASTIC!!!
Amazing amazing amazing. It's fun right off the bat.

Fun!