Great for adults and older kids... not so much for the wee ones.
Let me start my review by stating that my household is big-time into video games, both modern and old school. I took my kids to this movie because I knew they would love seeing Q-Bert, Pac Man, Sonic, etc. and would get a kick out of the video game setting for the storyline. And the beginning of the movie was great. We were all laughing and thoroughly enamored with the storyline. They've created some really likeable characters in really clever scenes. It was great.
Then the movie suddenly became incredibly violent. As in, in-your-face, really-scary, larger-than-life violent. And it wasn't just the man-eating alien bugs and the machine guns blasting repeatedly in the screen. Characters also were hitting each other, treating each other terribly, and destroying the things that made others happy.
At about this point, my 6-year-old had a total meltdown and had to be taken out of the theater. We tried bringing him back later, but that only lasted about two minutes before he was terrified and crying inconsolably again. He had to leave for good at that point, which was a good thing because it only got worse after he left. The 7-year-old next to us started crying at that point and begged his mom to let him go home.
Some of the parts that were particularly upsetting: massive machine gun attacks, Ralph smashing up Vanellope's beloved racecar while she cried and screamed at him begging him to stop, the buxom blonde machine gun woman beating the @#$% out of Felix while the candy vines laughed (she actually knocked out his teeth), a giant alien insect crashing through a glass window and murdering a groom at the altar on his wedding day, King Candy holding Ralph's head and telling him he was going to force him to watch while his best friend died... And the big screen made all of these scenes rather intense. The smaller kids just couldn't handle it.
Now, my 8-year-old was better equipped to deal with the intensity of these scenes and ended up really enjoying the movie--which truly did have a great message at the end. And from an adult perspective, I loved it. I even cried at the end! So for grown-ups and older kids, I'd definitely give it a thumbs up.
But I kind of wish I hadn't wasted the money and traumatized my younger child by bringing him to this particular movie. If you have younger kids--especially if they are sensitive to violence and characters treating one another unkindly--you may be better off waiting until this one is out on DVD so that you can watch it at home without the intensity of the movie theater, and where you can just turn it off if it becomes too overwhelming.