As a fellow person who writes their own engine for these things, I sympathize with the feeling of not having enough time to make more than a tech demo.  I can't wait to see what you manage to make out of it in the future!  The two-level shadow is neat, in particular.

Oh, and you probably know about this bug, but it seems that whenever you move in a direction that's not forward, the forward-facing sprite briefly shows up before switching to the correct one.

This looks like a nice tech demo. As mentioned, there isn't much game here, but the visibility "shadow" implementation is fun.

The build was missing the SFML Audio library, and wouldn't run until I provided that myself, so I need to mark you down on Linux compatibility.

Other than that, nice to see you around again even if you didn't have the time you would have liked to participate!