The only file in the install folder that the game seems to check for is
Your FREE BitBuddy™\Your FREE BitBuddy™_Data\RuntimeInitialize.txt
Thanks for the tips on the registry and LocalLow folders!
As a PowerShell command:
Remove-Item -Recurse -Force -Path 'Your FREE BitBuddy™\Your FREE BitBuddy™_Data\RuntimeInitialize.txt' ; Remove-Item -Recurse -Force -Path $env:LOCALAPPDATA\..\LocalLow\Funtech ; Remove-Item -Recurse -Force -Path HKCU:\Software\FunTech\