I need a hard but simple game made

I need a simple but hard game to be made for me. The site is going to be called the OneMillionDollarGame.com

The idea is the game cost $1.00 each play and when the person with the highest score when the one million dollar mark reach wins the million dollars.

Please give me your lowest price.

 

but what is the game itself?

 

Must it be a flash game or PHP based game (e.g quiz-like).