I just saw it. This movie was so much fun! I was talking about it the whole way home.
It's just like an 80's action movie. When Dredd throws a gas grenade its not just any gas, its bright neon yellow gas. When someone gets shot its not just a hole, it blows the side of their face off with a gratuitous stream of bright red fake blood with squirting sound effects. Incredibly cheesy one liners are spoken at pivotal moments. Action scenes are carried out with heavy metal or heart pounding synth music.
Seeing the movie in 3D is a must. Lots of scenes were made with 3D in mind and the slow motion effects look very beautiful. I thought Mama was a good villain. It's very rare that I think a woman is badass, but she really pulled it off well. I loved the shot of her smiling with blood dripping out of her mouth.