Update 1.3

Update 1.3!

• areas are now much shorter
  • old: 180 seconds, new: 60 seconds
• difficulty scaled down:
  • shorter areas should make it easier to get to later areas
  • enemy spawn rate, move speed scaled down slightly
• added clearer instructions to boss messages
• added a start screen for mobile to choose move mode
• fixed a bug where destroying every piece of the asteroid boss would cause the ship upgrade to spawn infinitely