I've yet to beat it haha, but well done in only 2 days!  I loved Space Invaders as a kid.  I like the guitar background track!  I assume that is you playing the guitar?  I had considered trying to do the same thing, but I'm pretty bad at playing guitar.  Our earlier builds had some of it in there though.  Good job sticking with it even after the bail out!

I'm normally not a huge fan of space invaders but I liked the twist that you had to "headshot" them. It made me pay more attention than normal to typical SI gameplay. Good splash of art to go with it as well.