I would not have guessed that this was your first attempt. It sounds pretty good.

There are a lot of "rises and falls" in it. There's a lot of silence, or rather near silence. It starts out minor and goes major back and forth, but there's a fair amount of sadness in it. (I may notice the low points more than some because I don't like atmospheric music. It's a personal preference. But for some games, this may be exactly what is needed, whether that's the kind of music I like to listen to regularly or not. But in my mind, when there's just a single note drone I tend to hear that as silence. Even a chord held for a long time tends to make me feel that way. I have a friend that likes to write atmospheric stuff like that and it's just not my thing. That being said, it may be exactly what's called for with some games.)

It feels to me to have too much of that for a menu. I imagine it being more like a scene out of the more recent Battlestar Galactica or something. Something where you have the pain of loss and fear but hope and as the music transitions you have different visuals that give more explanation of the contrast.

I pulled up the videos of This War of Mine muted while this track played and it fit relatively well. There were a couple spots where I would have changed the video editing a bit to make it fit the particular spot in the music, but over all it was a really good fit and with a bit more focus on the video than the music, I didn't notice anything with the music that didn't work.

Anyway, this is "usable" and I say that in the best way. If I had a video game that fit that mood, I could envision actually using this track. I could definitely imagine this going into a commercial game. Even if it didn't fit a menu or something, I could definitely make it work for a sales video like you typically get on Steam where you have a video that shows game play in a game like This War of Mine.

First impressions are that this sounds very professional. On a purely technical level, this sounds great. The samples are high quality sounding, and the dynamics add a lot and sell the piece quite well.

Musically its also a great piece. It uses silence and space as much as it uses notes which is especially important for something atmospheric. It does a good job of holding interest while not using a lot of superfluous extra stuff.

As for your subject matter, I would agree with the previous comment that menu music isn't what I would cast this as. For me its more of an exploration and discovery, maybe of a hidden landscape or something. Almost seems a like it could be in a metroid prime world or something.