You are not done yet. you made a big error in your new corridor. You do NOT place a check point right by where you have badniks, especially one's that can shoot!Ok sorry, I know I said this is the last update, but I was impatient and I made the level longer... I added to the level new corridor and placed checkpoints in more places...
Why did you also make it connect to right after the crushers on the conveyor belt?
By the way, an easy way to tell in game if you have good walls is if knuckles can climb them. if he can't and they don't have a flag that prevents him from climbing it, then you have a problem.