Stability and Sounds

Hey there Coilers!

I have been chasing around a few bugs that cause the game to stop spawning baddies (or continue spawning baddies during interstitials.)

I may have gotten them all this time, but I don't know for sure. If it happens to you, please let me know.

I also recoded the audio handling stuff so that different projectiles could have different sound effects with less code. That's mostly just to make my life easier, but also you'll get to hear a few new sounds. They're not final though.

Also.... A new power-up....

That's it for now. Have fun!