This show really ended up ending with a sad whimper. I think the quality started going down after the Turtles escaped the city after the Kraang had taken over. There was still a lot of good episodes, but there was some really meh-episodes during that season too, and too much time in that cabin. The show focused way too much on introducing characters and not enough on what to do with them. Like, what was the point of Spyder-Bytes or IceCream Kitty (aside from Mikey not being good around pets)? Some plots were never dealt with either, like Mutagen-Man, April's Mother possibly still being alive, HoneyCutt still alive in space, etc. I also did not like how the Kraang and Shredder were finally dealt with. Super Shredder was just a Doomsday-version of regular Shredder and didn't look as badass as the normal version of Shredder. The shipping with April and Donatello was toxic for the show. It's like the writers made her part-mutant to justify it, and when there was a chance for the writers to end it, they end up pushing it instead.