Create a text ui (create-ui-text). This will also create a canvas. Al ui must be on a canvas.
Create a game object called 'score manager'.
Have a event called 'add1toplayerscore'. After go to another state with the add int, convert to string and get ugii text. On the FSM you will need to make the event global (check box). the variable score can be an INT but you also need another STRING. That way you increment the INT but display the STRING.
So you create a collision box (like on a cannon ball) and when it hits something, you 'send event' to the 'add1to player score'.