Update before the long weekend

This update brings in some nice touches.

• I overhauled the UI
  • including some superfluous use of tooltips, because: reasons
• I provided a way to easily delete your save (you may never know...)
• I rebalanced the difficulty levels
• I brought in some skins and have them randomly cycled. It is my plan to eventually add achievements that unlock skins. Hopefully, this will whet your appetite.