Missing the pck for Windows and my antivirus flagged it as well.
Viewing post in Space Ignition jam comments
It might because you packed the pck file inside of it that it doesn't like it. I was able to open it and play a little bit just now. I got to the part with big floaty heads and killed them all, but when I went to the rocket it seemed to crash. Also, not sure if this was intetional, but the tank appeared as a untexture cube. Let us know when you get the file thing figured out. I'd love to give it another whirl!