The main problem I had with the game was the third level mini boss. There is a nice youtube clip that shows how to beat it.
That's classic. When I first got the game I had the hardest f*cking time beating that guy. I basically survived on pure luck alone, which meant I only beat him like 1/10 tries.
That was until I found out if you equip the proper weapon and go above him he's cake. It was only by accident I figured it out.
I haven't seen the YouTube clip, but I am guessing that's how they do it?