I thought it was better than the first one. There was more of a story eventhough the movie still wasn't perfect. Shredder has very little of the scars he had in the first movie. I mean look at the picture of Brian Tee here and that's how he looked as Shredder with I think a very small scar on his face.
Steve Amell is decent as Casey Jones but the movie made him a cop who just wants to prove himself. I would have preferred if Jones looked less like Amell walked straight off the set of Arrow. Maybe make him just a little more scruffy looking.
Bebop and Rocksteady felt like they came straight out of the tv show though. So that was a plus. The Kraang was done decently but with very little backstory. Kraang just wants to take over Earth and that's it. Beats the weaker villain plot of the first film I guess.
Splinter is under-used and his character probably would have been stronger if he was once human like in the show. Karai being his daughter was raised by Shredder was good stuff in the newer show. Without that Splinter, Shredder and Karai have nothing too engaging going on with them.
I thought it was a big improvement over the first. My 12 yr old niece thought it was terrible though and she's a fan of the newer show. So maybe you will choose her opinion over mine lol. I however grew up with the 80's show and was a big fan of the 1990 movie. Out of the Shadows is the best since the 1990 film I think.