Several times I've gotten to the end of this level and seen an indicator in the UL corner of the screen saying there's 1 enemy left, but if I run to that corner, there's no enemy there and I can't finish it. I have cleared it before, but maybe that was with a gun that shoots through walls/obstacles? Also, the music used in this level (and a few others) has a very short loop that seems to stutter, rather than looping cleanly like the rest of the music.

I absolutely love this game by the way! Keep up the good work!