So lately I've found that just about any software I snag from itch (or similar) will prompt this notice from Microsoft Defender. Usually VirusTotal comes back clean, but for whatever reason this happens.
From what I can gather, it's mostly because the software in question doesn't have a proper digital signature - Which, honestly, I wouldn't expect to be very affordable for small software developers.
So... It's probably fine? I guess? But my brain sees this prompt and just thinks "DANGER!! DANGER!!! WARNING!!!! FUCK, THIS WILL DETONATE YOUR COMPUTER AND SET YOUR DOG ON FIRE!!!"