Some Arch users have reported that the game was quitting at launch.
After some discussion in this thread, we have identified the issue as being related to which audio driver Allegro automatically selects (a possible upstream bug or an issue with the drivers included in some Arch versions). This was identified and a workaround discovered in this thread:
Create a file called allegro5.cfg in the same folder as the FLAT binary, and add the following lines:
Added #32 to Known Issues section in README.
This bug seems to be fixed upstream. I am able to compile and run the game without the configuration file on Arch x64.
Another user reported that he was able to do the same. We probably just need it confirmed by a x86 user.
The original reporter of this bug has confirmed that it now works for them. I'm happy to close this (but also happy to have it re-opened if anybody else finds they're still effected by it).