The MacOS release of 0.3.5.2 has no visible application icon, which besides the obvious also means the Finder has no region to double-click to open it (I had to right-click and select Open). The icon file itself is unknown, not just incorrect.
During gameplay, the Cmd-Tab application switcher shows what looks like a 32x32 version of the flaming U icon:
If no one on the dev team has a Mac, you can convert PNG to icns online here.