So, I've finished the fourth episode. It is pretty small, but good. And I've added some sonic stuff to E4M3 and E4M4, which contains rings, ring monitors, textures and even Dr. Eggman as a boss! Copyrights: Eggman sprites - Sonic Robo Blast 2; Ring and ring monitor sprites - Sonic The Hedgehog 3D; Level textures - Sonic Robo Blast 2. Enjoy!