thanks for the quick reply @ eXpl0it3r
I am doing this with a friend of mine, and from my experience with OOP (which isn't that great) is that if the plan is not good then I will get stuck, I situations where I need to get to a function or variable or object that I can't get to, because the hierarchy wasn't build correctly, thats why I wanted to build an almost perfect plan where I won't get to this situation.
Are you saying that I should not use the STRATEGY pattern?
also I don't understand how I am supposed to move the doodle, is he moving upwards? or is the screen and all other objects moving downwards?