Okay I initially had some issues getting prone to work without the game closing, but I scrolled down a bit and saw your comment on the alternate control scheme so I went back and gave it a shot and sure enough it fixed the issue!
Genuinely this was such a cute game, the first time I slipped on the duck I actually laughed out loud at the animation. Also the music being a mix of Christmas music and stealth/action music was perfect. Seriously this took me by surprise in the best way. Great job!