Quoted from lpeters82:
I think I'm the only one complaining. I'll start out by saying, I 100% agree with you. The inserts represent each villain just like in Deadpool. However, look at how well the inserts blend into the artwork on Deadpool. Most of the inserts look like they were place there by the playfield artist. That's one of the reasons Zombie Yeti is my favorite artist. He is the cream of the crop for incorporating shot lines and inserts into his artwork. I'm not seeing the same attention to detail in Teenage Mutant Ninja Turtles.
I am sure he thought about it but prob just not enough room to make the inserts bigger by the enemies. I actually really like the small dot inserts by each guy. The best insert for me and how ZY implemented is the final wizard mode Cowabunga. Its a speech bubble from Michelangelo while hes fighting shredder. Thought that was neat. I dig it all.