I found it.
Vosmug 2015 - Demo Version v.0.1.1
You are correct, it is not Flash. I had been downloading various flash games when I originally downloaded it, some of which were converted into exe files. (I wish a lot more Flash games did this. Yes, I know it limited them to Windows… but now that Flash is dead, so are a ton of flash games that were never ported to console… now trapped as swf files that even flash emultators don't correctly run… I miss the flash games that never made it into the massive archive of flash games that were lucky enough to be preserved…)
Since GHV - demo 0.1.1.exe was barried in the depths of my flash folder (animations, games, music videos…), I must have mistaken it for a converted flash game.
What engine or code was it built in so I can put it in its correct place?
On a side note, I have no idea where I got the demo. Maybe Newgrounds, if you ever uploaded it there…
In any case, I'm glad it was finally released; even if I missed the début.