Fixed crash with difficulty logic - Version 0.3.1

Because I'm a newbie developer I messed up some logic and had to fix it or the game would crash randomly. So that's fixed.

Changes in Version 0.3.1:

• Was boring with how slow it was at first. So made adjustments to the difficulty.
  • Takes 3-minutes to hit max difficulty now.
  • Every 20-seconds it ticks to be harder.

Okay, for real now. I am going to bed knowing that this is fixed. LOL