In an attempt to launch everything through steam on the steam deck I used lutris to install the humble games collection client, downloaded ghost song, and added the .exe to steam as a non-steam game. The game does not seem to launch this way, I'm not sure why or how to dive deeper but I get as far as the Unity spash screen and then a resounding C2D or C2BPM. Some games work better in desktop mode, others in game mode, this doesn't like either.