Played Cobalt Mountains. Pretty short. Only edit I'd suggest is to have that optional area, relink to the main course, before the boss fight, so you don't have to back track. Pretty cool level other than that. Not too difficult, and not hard on the eyes.
Actually you're not supposed to be able to go that way, but we screwed up the positioning of the bomb thingy.
There is another way into the ice cavern that you have not found. The level should be reupped at this point, with the way you entered closed off properly.