Numbers! A simple numbers game

• `Left-Click` a tile to select it.
• • When selected, operations adjacent to tiles will appear. `Left-Click` an operation (+ or -) to perform on the adjacent tile. That tile will become selected and the process repeats
• When you are happy with your solution press `space` to accept
• • If your solution is correct, the tiles will be removed and new tiles will drop down from above
  • If your solution is incorrect, the tiles will flash red and deselect
• `Left-click` on a previous selection to unslect tiles to that poin