My requirements are as following;
GUIs: Different interfaces like main menu which includes different buttons like play, high scores, Shop and how to play.
Play: by clicking this button player can go to choose the bike window and after this go to choose the location window.
High scores: When user press this button, he/she can check the highest score of the game and his/her own score and level/ranking.
Shop: By clicking this button, player can buy different weapons and bikes according to his/her score/level.
How to play: By clicking this, a page should be opened, where user can read the instructions regarding the controls.
Accomplishment of the given requirements.