Hey, I gave it a play.  It worked (thought I did fall off the level on my first try).  Got a score of like 60.  I was able to jump up on that incline and just kill the balls at will.  But I wanted to move around more.  But pretty much it was just go backwards and strafe since all of the enemies just come right at you.  Would be good to add some platforms and cover to jump on.  But this is a good start!