This game is 100% off for another day-and-a-half or so.
A few ProtonDB reports say the native Linux version of this game doesn't work, but it Works On My Machine™ so far. Maybe other reports were from before Steam started using Steam Linux Runtime 1.0 by default for native games.
Anyway, I kinda hate the art style which is probably supposed to be the selling point. But it was $0 and I wanted to see if it runs.