Sorry, it's been a while since I ran the game on Linux without launching it from Steam and forgot to include run instructions.
You should be able to run the game like this:
path/to/steam/bin32/steam-runtime/run.sh path/to/game/Locomancer.x86_64
However, when I just ran it, it kept spewing about failing to create a pipe to the Steam API, so I might need to rebuild it with the Steam API ripped out. I left it in because it's used for multiplayer/workshop support and not DRM.
Let me know and I can rebuild it if necessary.