I've had two problems so far. First, in section 2, the firefly took about 15 minutes to come out of the tail. Second, in section 3, the rocks will not hop out of the path. I don't know why I'm having so many problems, but I've wasted plenty of time trying to figure these things out.
In section 3, I had to pull the creature's tail before the rocks started hopping.
In section 10, I had to pick up a pitchfork in the first area (underneath the bat) and use it to hold the chain down in the second area (where you turn into the bear).
Also in section 10, pick up the torch on the patch leading to the fire.