Well, after a whole day struggle, I give up, I found that not every one can be 'Numerical Game Designer'.  My game is a tower defense game, how to balance the tower and enemy, and how to design the game pace, both are problems :)

Anyhow, I am satified with the final result, it is buggy, I know, but my victory is I have finished it. During the debuging, I nearly lose my patience, by chance, my son came to bother me, he is only 3 years old, and know nothing about computer game, but he was attracted by the car in my game, so he claimed me to play it again. At that time, I suddenly found my game is not that bad :) Of course, compared to commecial game, there is a long way, just for fun, it is enough. And it is also my first tower defense game, I can do it, maybe next time I will try dota :)

This time I use kivy, I know it is not as friendly as pygame, I will try to package it, good luck to me :)