v0.2.0 - Difficulty scaling + Circle of Pain

The difficulty has been tweaked to make it harder and require buying power ups to beat the game:

• Decreased amount of health a potion restores from 100% to 40%
• Reduced both Wizards Hat and projectile count buff so you can't get a ridiculous number of hits from each weapon by maxing them
• Increased health and quantity of mid-game enemies and bosses
• Fixed a couple of units dropping experience orbs for every unit killed when they were only supposed to do it some of the time

On top of this, we have added a new weapon: The Circle of Pain!  This new weapon does a small amount of damage to all units in close proximity to you.  Early game in particular it will make dealing with mass skeleton waves a breeze.  As you level it up, it does hits increasingly large areas and hits more frequently.

Misc changes:

• There is an in-game pause button so you can pause the game without pressing escape (particularly for mobile where you don't have a keyboard!)
• Fixed failing to load music/sound files stopping everything from working at all
• Fixed typo in the level 8 description for Dagger
• Added the current version number to the bottom of the title menu