Just finished! I thought it was well executed and intuitive enough to pick up pretty easily. I wouldve like some sound effects, idk if there were any but i didnt hear anything. The general design of the puzzles was very cool however once you understand what to do it just becomes following a set of instructions, which is more tedious then exciting or thought provoking. I will give credit for the first and second puzzle, the first obviously introducing the mechanic and the second adding the ability to move the light around, so the puzzle was expanded on. I dont think the 3rd puzzle added anything new so as soon as i saw the potions i knew what i had to do and there was no catch or revelation moment. I think it would have been a good opportunity for an "assumption", I assumed i knew what i had to do cause of the first puzzle but there was no catch that subverted that so it just became a set of instructions.
Overall I do really like the idea of following clues hidden in the shadows and I think this could be expanded on to make a really interesting full game! Great work