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 'hard utsuge' like Houkago no Futekikakusha. Each of the first three heroines has a bad and a normal ending, and no matter what you choose, darkness awaits. The fourth heroine, the angel Aine, is the true heroine and only has one ending (the true ending) which is also bittersweet, though there is some sense of salvation for the protagonist, albeit at a price.
The first three heroines are the aggressively helpful osananajimi (who is the only one of the heroines who knows his past) Naruko, the soft-mannered but somehow gloomy Yuri, and the standoffish Minamo. Thankfully, only Naruko falls into an archetypical role (osananajimi characters have a very limited range of roles), which is nice for someone looking for something with unusual heroines.
This game focuses on a sort of tug of war between the apparently apathetic Kirinokojima Tomoe, who actively loathes romance in general, and the optimistic clumsy angel Aine, who believes in romance as the ultimate force for human happiness with all her heart. Tomoe is kind-hearted under his apparently apathetic exterior, inevitably caring about what happens to the people Aine wants to help, but his belief that romance only brings suffering and is a force for evil in the world is so strong that he is constantly wavering on whether to go along with Aine or not. This conflict, though it is not one born of malice, defines the main storyline, as the characters worry about what is best for the people involved.
The first six chapters of the game are the common route, and each chapter covers a different romantic mess that draws Aine's attention. These messes are never simple nor easily resolved, and regardless of which path Tomoe chooses in the end, nothing turns out perfectly. The seventh chapter covers the heroine routes, which are much more intimate and have an impact that quite naturally surpasses that of the arcs of the common route.
I advise anyone who plays this game to play Naruko's route third, regardless of which of the other two paths you do first. I say this because Aine's (the true path) splits off immediately before you would otherwise head into Naruko's route...
Yuri's route is pretty... sick-minded. Sorry, the writer of this game probably has a serious mental illness, and I shouldn't be insensitive about it, lol. Anyway, there are hints of what Yuri's conflict is in the common route, but it escalates rapidly once you actually get to her route and her personal issues are laid bare. Tbh, Yuri's route is the most horrifying of the initial three routes for reasons that become obvious to anyone who plays it, and I wept at the normal ending and was somewhat disgusted at the bad ending (both times).
Minamo's route is a bit less psychotic than Yuri's... but in exchange, the issues are more 'worldly' and familiar to the average reader. The central conflict involves Minamo's work as an idol and a combination of her past issues, family issues, and the inevitable problems of a celebrity in Japan getting involved romantically with someone else. While this path is milder than Yuri's, it is a lot easier to empathize with, and it also epitomizes Tomoe's nature to a greater degree than the other two paths.
I didn't bother with the bad ending this time, instead going for just the normal one. The normal ending is bittersweet and strikes me as the ending that most fits Tomoe's personality outside of the true ending. It is sad, though.
This is by far my least favorite path in the game, though it isn't just because I dislike osananajimi paths. I won't go deep into why I didn't like this path either time I played it, because I don't want to spoil anything important, but I will go ahead and cover the spoiler-free issues. This path is the only one of the first three paths that actually touches upon the reason for Tomoe's apathetic/asexual personality, and it also is the only one that touches upon the truth of what the angels work is. As such, it is absolutely vital that you play it before the true route even if you want to go straight to it, since the explanation isn't repeated in the true route. Moreover, Naruko's route's normal ending serves as an example of the game's true central conflict that is vital for understanding the true route.
What can I say about the true route/Aine route? It is by far the best path in the game (though the ending is still deeply bittersweet), and after you finish it, there is a sense of salvation for Tomoe that doesn't exist in any of the other paths. I say a sense of salvation, but it is salvation at a cost, as is typical of every blessing any character in this game experiences. This path reveals the fullness of why Tomoe hates himself to the point where he rejects all possibility of happiness for himself, and, to be honest, I replayed the rest of the paths solely so I could re-experience the heart-jerking events of this route in the same manner I did the first time.
I can recommend this to someone who wants catharsis and doesn't mind a darker atmosphere than you would see in a nakige. It is also something I can recommend to utsuge lovers (if you liked Swan Song for the emotional elements, there is a good chance you'll like this). I do not recommend this for people who want undiluted happy endings.