It's hard to appreciate it as much tbh...
Casey was a useless moron (everytime he's on screen is a waste of time). Shredder was a lame ass alien brain, ew. Their sewer was too stylized and sci-fi farfetched. Too much magic, too much planetary space-travelling, Raph sounded like a 50 years old chainsmoker instead of a teenager... and so much more.
I absolutely adore their Usagi Yojimbo though. they nailed it perfectly.