I like the aesthetics and the old RE charm! I couldn't quite unlock the 4 valve door unfortunately. I couldn't get far enough from the monster to turn around and use the flash but I see what you were going for and I think it's a great concept nonetheless!
About the "Windows Protected your PC" message, I believe you need to purchase a Windows code signing certificate and sign your executable for Windows to consider it trusted. For what it's worth, I've never seen anybody bother to sign a game jam game. This message has popped up for every jam entry I've downloaded, not just yours.