I didn't read most of the replies, but in my case I felt like I had very little improvement for the first several years I was in the hobby. Total Nuclear Annihilation and Hardbody were the games that I'd credit with making me a slightly better player. Having to focus on individual targets really helped me get better at hitting ramps and orbits. I'm now capable of playing a great game, but I still have many games where I feel like a total novice. When you are saying "complete" a game, that sounds to me like you are doing pretty good. I feel that only really good players will routinely reach the wizard modes on games. In my opinion if you are reaching wizard modes often, you need to set your game up more difficulty.