I watched the previous TMNT show as a kid and was more than eager to see a more serious take on the subject, which I was led to believe this incarnation of the Turtles would provide (reading reviews and descriptions of the show). Alas, that wasn’t entirely correct.
While a bit stronger in the plot department (multiple levels of plotting, that stretched from multi-part episodes, to seasons and plots covering the whole series) characterization was still shit. If the previous TMNT was the kids-version of the turtles, the 2005 TMNT version sadly wasn’t the grown-up version, but the teenager one. The characters exhibited all the emo-like emotions (gloomy, pathos-dripping speeches, endless self-questioning etc.) that get mistaken for maturity by some, but are merely the signs of teenagers growing up and coming to grips with the world around them.
While fitting the age-level of the turtles in the show, I found it annoying enough to stop watching the show around episode 13 of season 4 (teenagers might find it fun to watch, I don’t, since I’m long past that age). Not all turtles acted as annoying, the science guy and the comic book fan were actually fun, but the leader guy and the aggressive one sucked so much joy out of the show, that after some point it just felt like chore to watch.