0.3.0 Update

Hopefully the final update for the demo.

I polished a few more things and optimized some code. The key feature of this update is that I decided to add a visual indication for the power ups duration, so the player can have a sense of how much time there is until the effect ends. It's basically a glow around the player's view that fades away according to the power up duration. I also polished the X-Ray effect, making it fade out with time as well.

===Changelog===

• Increased power ups duration in all difficulties
• Enemy footsteps cannot be heard from too far to prevent disorienting the player too much
• Intro cutscene can be skipped
• Added visual feedback to indicate power up effect duration