I was arguing with my best buddy today about it. I consider that "Learn To Fly" is waaay easier, and does not need much attention. I seek difficulty in games, I like to beat them as a principle, as a core of my geekness. "Pirate launch" has lesser achievement and upgrade options. "Pirate launch" clouds are not making funny faces. But game needs your attention, control, grip. Getting to the end of level in "Learn to fly" could be done with eyes closed. Just go in wawes left right left right left right with amplitude needed. Whole process is boring. Nothing differs, nothing happens. You just fly, listening to boring music.
learn to fly is better in my opinion. The upgrades are more noticeable and its a penguin with rockets attached, how can you not like that. Pirate launch is still a good game tho. =D
Learn to fly was a quite good game, but had nothing impressive. Learn to fly was good too, but I still remember it better. So I think Pirate Launch wins.