v02 Release - Explosions and other things

Good news - it looks like you are actually in danger now because the lasers explode whenever you get hit! (Don't worry, it happens for the enemies too). Plus, when you die, there's an extra big explosion. Many thanks to this superb video linked for the inspiration.

Features in this update:

• Explosions added
• Fixed starfield background on end screen
• Added player damage images
• Disable buttons after single click

More to come, guys. Sounds are next!