And I don't know what is the problem with other people. I have fun playing the iPhone version because of achievements, able to play any of the completed Sigma's Fortress stages anytime, difficulty level, save data instead of passwords, and in-app purchases (which I won't ever use). I am GLAD that I purchased this.
EDIT: Okay, there are some flaws in the game involving achievements. I defeated Vile with the Rolling Shield but I didn't get an achievement for that. --- Don't mess with the thunder dragon. Xbox 360 Gamertag: NejiHyuga900