The installer ran fine, but the installed application just closed immediately when run. When run from the command line the following error was reported:
LSOpenURLsWithRole() failed for the application /Applications/PyxelEdit.app with error -10810.
I opened up the package and ran the executable directly, and it opened a terminal with an error about being unable to make a copy of itself named PyxelEdit_32, due to insufficient permissions. I changed the permissions on the MacOS folder within the package so that it was world-writeable, and that fixed the problem.