一个击键游戏。运行游戏之后，屏幕上将随机产生一个字符，然后用户根据这个字符敲击键盘上相应的字母，如果二者吻合则分数加1，否则减1。另外，过了一定时间限制用户没有按键，分数也减1.

同时，还可以选择游戏难度，用户首先选择难度，然后开始游戏。-A keystroke game. After running the game, the screen will randomly generate a character, then the user tap the basis of this character the corresponding letters on the keyboard, if the two match then the score plus one, or minus 1. In addition, over a certain time limit user does not have buttons, scores are also minus one. At the same time, you can also choose the game difficulty, the user first select the degree of difficulty, and then start the game.