I think this game has a weird learning curve and it has some odd spikes of difficulty here and there, but it grows on me with each playthrough. I love the one sequence nature of it, and it has some pretty tight level design. I like Zwei more in most regards but the challenge of this one is what really sets it apart for me. I wish I felt more for the music, like flight is such an incredible song, the best in video games, but every other song is a bit forgettable to me. I think my favorite level is the tunnel sequence, it's so intense and the boss in that is killer. It's definitely worth learning and beating