I've just played a game of this PC version and reached level 20. Obviously, while making the C64 version, which took a few months, I gained a lot of practice and, above all, mastery of flying, which is what is needed to succeed in this game. Personally, I've always used the keyboard; at this point, I suggest you try it yourself with the keyboard to see if you get better results. Otherwise, if you have trouble getting past level 8, you'll have even more trouble in the later levels. The game has been tested by my collaborators too, and the difficulty has been thoroughly evaluated. I can't change the levels because only one person is having difficulty. If several people complain about the game being too difficult, then we might consider making changes. I'm referring to the C64 version, however, since I'll most likely never touch the PC games again, given the lack of interest they've shown in recent years.