I'm all for a game that makes math interesting (I'm a math teacher) however I have one *major* concern. All of the answers for the quadratic functions are the exact opposite of what they should be. For example, x^2+5x+6=0 factors into (x+2)(x+3)=0, which means x = NEGATIVE 2 and NEGATIVE 3. The answers you ask me to plug in are the opposite signs of that.
Maybe you can change it into the two binomials that the quadratic factors into. So instead of asking what x is equal to, just prompt with x^2+5x+6 = (x+__)(x+__) where the blanks should be the positive/negative numbers that you're asking the player to input as it is.