[neatoman]

The problem with doing a bunch of movie spin-offs is that I don't think a TMNT spin-off has ever been all that successful. Keep in mind, Marvel's attempt is pretty much the only successful one yet, and aside from DC they're the only ones with a basic framework build on. The mere fact that Spider-Man, Captain America, Thor, Iron Man, Hulk, etc were already successful and (more importantly) connected through crossovers long before anyone thought about putting them into movies. There are decades of material to work from, I (and they) already know how it works, it's right there to read.

With TMNT, what do you honestly have? A few spin-offy micros and minis about relatively few characters? At least that Venom movie makes sense to work from when you remember there are 150+ issues of solo series to work from, here you'd pretty much have to improvise. Not that you can't it like that, it's just not a surefire method.