Not bad
Get it straight, this movie is not for children. If you let children watch this, you are dumb. I never let children see anything on NG unless I preview it first. Despite violent content the original television series was more appropriate for children, and even though the original ninja turtles were kid-friendly, the older TMNT fan base is growing up and enjoys more adult content, and this flash submission, which is rated MATURE, is a reflection of that.
But anyway, a long time ago I watched an episode of this series for the first time. I didn't like it at all, and I didn't even think it was funny. It must have offended my sense of decency... but I loved this one! It was random and crazy. Michelangelo painting the Sistine Chapel in the sewer was a twist I enjoyed. (In fact, when he was looking at his messy, green turtle hand for a moment he appeared to have a great epiphany. I actually thought that he was going to repaint Adam's human hand into a turtle's hand to symbolize “The Creation of Turtles” instead of “The Creation of Man” or something... I don't know.)
However, I really hate the subtitles. I read too fast and it often messes up the punch lines because timing is important and the humor just cannot be conveyed through text. If it were my movie I would just ditch the subtitles altogether and say, "If you don't have sound, too bad! You couldn't fully enjoy it anyway."