You may see a Windows Defender SmartScreen warning the first time you run the launcher. This happens because it's a new, unsigned application — Windows hasn't built up trust in it yet. The more people download and run it, the sooner Microsoft will recognize it as legitimate.
The only way to bypass this immediately is a code-signing certificate, which costs up to $250/year. If donations ever cover that, we'll happily get one.
For now, just click More info, then Run anyway.
Our launcher is completely clean — you can verify it yourself on VirusTotal.