Surprised this wasn't posted here before. This is a shooting game by lol_rust, creator of .flow, Shojo Kidan/Gidan, and Milya.
Here's a gameplay video: https://www.youtube.com/watch?v=xvXvAscyVWo
And here's where the game can be downloaded from: https://www.freem.ne.jp/win/game/19074
lol's website, which AruMa KeteRa strangely isn't posted on yet: http://rustlimbo.webcrow.jp/
It's already completed? I thought it was still in development
Music sounds dope (as lol's music always does) but the rest looks like a halfway decent shooter game.
So what's everyone's theories on what's going on in this game? It's pretty vague but there does seem to be something implied by the text scrolls, mirroring of levels, final boss, and probably the in-game diary (I haven't had a good look at that yet though).
The game as a whole is very .flow-reminiscent, both in aesthetic and 'plot'…especially the Eaters level. That could just be favored aesthetic on lol's part, though.