Blue Beam! v0.2.1 update

Numerous small updates to the game.

• Enemies have new and different sounds now. The aliens now don't sound like crumbling rocks when they die.
• General tweaking of numerous object properties to make the game a little more strategic.
• Fonts are now outlined to align with the late 70s/early 80s look.
• Bonus point powerups now give more points.
• Removed the game over screen.
• High score tracking has been fixed.
• Title screen now has an animated prerendered rotating 3D model, but this will be replaced for something more retro.