On the NPC blocking off the next area problem, maybe you could make it so that clicking the arrow to the next area temporarily disables solid properties of NPCs, making Cuboy be able to walk through them?
With the reaper and skeleton spells constantly active, drop soul jars as soon as they reload. In the mean time, use concrete fists and confusion. When it's reloaded, use earthquake. I only stopped playing survival mode with this combo because it was getting boring. + this so that the last badge is a piece of cake.
Minor glitch: Once you connect the rooms with the orange and green guys, go to the orange room and look through the door at the green room's ceiling light. I should be orange. Walk through, and it becomes green.
 "Cuboy: Cubeture 2"){kind=icon}
 "K.O.L.M. 2"){kind=icon}
 "Katwalk"){kind=icon}
 "Accelerator"){kind=icon}
 "Little Wheel"){kind=icon}
 "Cat God vs Sun King"){kind=icon}
 "Bubbles 2"){kind=icon}
 "Book of Mages: The Dark Times"){kind=icon}
 "Elephant Quest"){kind=icon}
 "Disappearing Circle!"){kind=icon}
 "Jetpack Jerry"){kind=icon}
 "Run Elephant Run"){kind=icon}
 "ELEPHANT RAVE"){kind=icon}
 "SHIFT 3"){kind=icon}
 "Five Minutes to Kill (Yourself)"){kind=icon}
 "Case File 1"){kind=icon}
 "Antimatiere"){kind=icon}
Good idea! Feel free to bombard our programmer with these suggestions.