I played the game on Linux. It worked well, narration seemed fine and volume sliders worked well. I was able to complete the entire game.
I liked the puzzles quite a bit. The apple was particularly tricky for me, much harder than the later puzzles. Perhaps it's because I learned some during solving that puzzle, or perhaps it was actually the hardest one. Either way, it was enjoyable to find each solution. Generally the pacing was pleasant and the difficulty was perfect for me.
A mouse sensitivity slider would be very nice for a game like this; I was able to set the hardware DPI to something close to what I wanted easily enough, but I think this would be a big, and hopefully simple to implement, usability upgrade.
Another easy frustration to eliminate is not being able to see the boundary. The mouse will not extend fully into the star field, and when it hits the invisible boundary it usually causes the mouse to register as stopped. Putting a visible fog or something around the boundary would pretty much fix it. I think occasionally it would also not process input for a bit, my mouse would warp to a new position and it would terminate the attempt. Perhaps there's an easy way to amortize the mouse movement based on delta time that would make that more forgiving.