Thanks for your feedback I really appreciate you comments. The case is that this game has been made for a global competition ( Ludum Dare ) in which you had 48h to create a game under the theme "minimalism" so I decided to go for a game like old games where graphics were minimal and the gameplay options too but what made that kind of games so fun was that they were really easy to play but really really hard to master and this is what I've tried to achieve here. In fact I agree with you that there's a huge difference on skill level on the later levels and if I have time to improve the game I'll create a better learning curve so the game becomes more natural and satisfying.