This is perhaps one of the few games from my first five years playing untranslated VNs that isn't a chuunige that I remembered vividly.  I decided to pick this up again because I wanted some good catharsis, and I was tired of waiting for Mangagamer to get off their butts and actually release this.  Boku ga Tenshi ni Natta wake is what is called a 'soft utsuge', in the sense that there are no good endings but it focuses more on the bittersweet sorrow rather than the absolute despair of a 'ha