If you do not have writed one single line of code in your life, you will not do a checkers game in one week.
It's necessary to know all the bases about programming.
If you have some programming skills like one year or two doing it for yourself or at work, you could do some puzzle or shoot'em'up in about a month.
I'm a professional programmer. In the 90's I have programmed a shoot'em'up in Z80 assembly (Cosmic Battle:
http://msxdev.msxblue.com/m... but I have not finished. I have started porting my game to C#. Half of what I did in two years, I could do using XNA during only a month.
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