I have been working extensively with Unity for the past 6 months on several projects, so I am very familiar with creating simple Unity projects and debugging projects others have made. I have already reviewed the code you put up, and aside from a few syntax errors it does run, so I would be glad to share those errors with you.
Here is an outline of the project I have created with your code:
I have a project with a player object and a pickup object on a plane. The player object is moved with the arrow keys. When the player collides with the pickup object, the object disappears and the count is incremented. If the player falls off the level, the Game Over text is displayed, and a button is shown that restarts the level when pressed.
I hope this is what you had in mind, at least in terms of functionality. Have a nice day!
Aaron Ballard