Thank you for the review! I interpret shadows and void to be similar if not the same, my lore is that souls either have resolved emotions (go directly to afterlife), unresolved emotions (the ones you are mainly helping in the puzzles), or they are emotionless (essentially evil spirits who thrive in the void and need much greater intervention like in the final level to get to the afterlife). As for alchemy, I interpreted it as changing from one state to another. One of the core mechanics in this game are the emotion flames which change your emotion (color) to that flame's emotion.
Since I made all my main mechanics and did all my level design in the last 2 days, I was not able to add the shadow entrance area as I had planned for the story which sets the setting for the game. I had also planned to introduce each altar (and emotion) one level at a time but I wanted to focus on the quality of the puzzles rather than quantity of puzzles for this demo with the limited time I had :)
I will be sure to add lore into the next version of the game!