If you've got fond memories of the Teenage Mutant Ninja Turtles, specifically the cartoon and action figure version from the 1980s and '90s, then do I have the fan game for you. Teenage Mutant Ninja Turtles: Rescue-Palooza! is a homage to the arcade and NES games starring the Turtles, filled with voice lines from the show.
Shredder has decided to celebrate the 30th anniversary of his rivalry with the heroes in a half-shell by kidnapping their entire supporting cast, so you (and maybe a co-op buddy) have to rescue them all, after which they become playable characters. There are 60 of them, which means basically every character you remember (even Usagi Yojimbo, the rabbit from Stan Sakai's comics who met the Turtles in a crossover).
It plays a lot like the old TMNT arcade game, which is to say it feels like Golden Axe. Bebop and Rocksteady are still jerks to fight, and after I rescued April O'Neil she hit Shredder with a microphone. This rules.
You can download it from developer Merso X's website.