Small updates

I noticed that the cursor started one column left of the middle, so I adjusted it to the right one column. I also moved it down one row so that the calculation is consistent, although the cursor can't be centered vertically while pointing up and down since there's an odd number of rows. 

The game over screen also only shows the game over announcement and prompt to start a new game. I removed the score from the game over screen since it's in the upper-left corner of the device screen.

Cursor position:

Game over screen: