Nice idea and i respect your afford on making this but still, the controlling shouldnt be a "skill" which you can upgrade, it just makes people leave before they are high level enough to buy it
its pretty good, make better looking menus, you should use more time on them, maybe look tutorial how to make nice text and stuff. I assume you use actionscript 2 so this should fix the cheat:
if (ASnative(800, 2)(2)) {
//what to do with cheater
}
i found it on Emanuele Feronatos blog, you should also check it