Very cool unique game idea :-)!
This was a fun and clever puzzle game. The puzzles increased difficulty steadily and introducing new options and features. Was fun to find out how to solve the levels using the options available.
Maybe one very minor downside was that targeting the shadows with the mouse was not always easy and sometimes just went wrong but the quick reset helped not be frustrated.
The idea/theme of light & darkness using these shadows was very unique and clever invented. No UI to be seen..good. Good example that simple visuals can still be excellent and create a fun game. Nice simple visual style and the music really fitted the puzzle levels well. Relaxing and giving it a good ambiance.
I would say: job very well done for this jam :-)!!