Why should we include this: this is a Touhou open source clone / fangame. Currently we don't have many games of this specific genre (danmaku / bullet hell) in the repo; most of the other Touhou games don't support Linux natively.
Open source: Yes; source code licensed under MIT, soundtrack under CC-BY-4.0, other assets under CC0-1.0.
GitHub repo: https://github.com/taisei-project/taisei/
I already have working package for personal usage. If the game gets accepted for inclusion, I will step up to maintain it.