wow. that was amazing!
Although im not much for sad endings to good series, this was just way to good to dislike in any way!
Graphics: best that they come for sprites, up there with my other favorites
Style: your series has had its own unique feel, ive really enjoyed it even though its sad.
Sound: all sound effects were well done and i loved the music! Very nice!
Violence: needless to say there was plenty of it and it was all very well executed (im glad you didnt have blood throughout this, i personally think it would have dragged it down).
Humor: going with the way the story is there isnt much in the way of humor... unless you like watching turtles flying into barriers :)
Overall i give this full marks it was done extremely well, in depth storyline and always keeping your attention on it! its too bad you've decided to end it but after this one you cant really expect anything more -_-
good job and keep up the good work! ill be watching for more from you!