Great interpretation of the theme. The tutorial animations and levels are a great help to understand the main mechanics. I like some of the finer details like achievements and having the cursor change color when aimed at something. One of the things I'm not a fan of would be the need to exorcise the wisps to unlock further levels. I can see it being an extra challenge, but adding precision shooting into a puzzle game doesn't fit very well to me. The objectives are also not shown before finishing the level, so I don't know what to aim for at the start of each level.
Overall, I think the game is executed nicely, especially after considering the limited time available. Good job!