Good difficulty curve

The early levels are pretty easy, but toward the end, at the snow level, things take a turn toward difficult and they get a lot more serious. They require a lot of timing and thought, and there's a lot of times that require some fast reflexes. Some of the levels let you skip some of the more difficult parts. I found one by missing a barrel shot and finding a short cut. Sometimes you find an animal friend and he makes the level a lot easier. But if you die you lose it, and sometimes you can't go back and get it.