The download page says "0.15.4".
The downloaded game says "0.15.4" on the title screen.
In your announcement about the 15.5 redeploy there was mentioned that it would be avaiable to all platforms and your game servers were mentioned. Since onc GameJolt you only made 15.4 avaiable, I ASSUMED there would be an automatic update from 15.4 to 15.5 and did what I described in the post above. However, I know now that is not the case and 15.5 is just missing on GameJolt.
I hope to see it soon there, thanks for your effort.