Oh, you can keep the names as they were. It just bothers nitpickers like me, if never an hint of an explanation is given. And boys having a girls name and girls having a non-name is something to stumble over.
The boy could have been made fun for the angelic sounding name and thus only uses a short form. Or since it is postapocalpytic. People usually have better things to do than running around with their passports. They have no last names eithers, after all. So an introduction could be like:
Your name is what? That is not a name. - Duhhh. It is not my real name, I chose it myself! It is a new world, didn't you notice?
Or. That is an odd name for a boy. - That is because it is a nickname, doofus.
Whatever you like. Even subtle as one of the kids carrying a school bag with a name tag on it that spells the full name. But if you do nothing, I have to assume it is a world were these types of names are normal. Or worse, I could misinterpred the gender of your toons. All of this could of course be intentional. Like foreshadowing with the whole angel topics.
Names in such a setting can be anything. Including origin places, occupations or making fun of a activity the character did. In postapocalyptic, you might be called Rpg or Pixels, if you talk about your preapocalyptic activities.
Since it is your hobby, it should make fun to you foremost. There are just too many indie devs. Even if you make a good game, have an inviting game page, a free game, stunning social media ... you still have hundreds or rather thousands of people that are the same. I could play a new vn every day, and never accidentally stumble over yours. And I do have a backlog of literally hundreds of games to play. Maybe I should comment less and play more ;-)
Regarding your art style. Yes, I did say that intentionally, of course. But also because in my opinion it is like that. It is just not appealing to me (but not appaling either...) There are not many objective criteria to look at art. I can give an example of an evolving art style. There is a webcomic, questionable content. It runs 20 years now and the artist is self taught. You can look at the style evolving by looking every 100 pages or so. (he has over 5000 now). Or you might know the anime Shin Chan as another example. That one looks not quite like other anime...
Oh and it is pixel art to me. It is not very artsy and not the usual kind, yes, but you draw in low resolution, so I can see the pixels and stair case effects. The style is drawing-like-a-kid. And in this day and age, if I can see the pixels, it is intentional. (ok, maybe it is just low resolution art and not pixel art, report me to art police, if you must)
As you might have noticed, i am a forum lurker. So I do see lots of topics by ... "aspiring" developers. It was not a compliment for compliments sake, of course you are free to see it like that. As you are free to take offense by people not liking your game or your art. But you go at it without the attitude, that i observe so often. You know your current limitations and seem to have a plan. Compared to those others you are professional and they ... are not. I diss them because they project this delusional attitude: I made half a line of code and managed to press export on a game engine, thus I am a developer; why is no one playing (buying) my game. Seriously. If you dig in the forum you see lots of such threads. And if you take a look at the game, you see the why in the first seconds and question the meaning of the term indie game developer. Maybe they think it is (indie game) (developer). While I see it as (indie) (game developer).