Hi and thanks for this game!
If you'll make any update it in the future eventually, it would be nice to have also an option to switch on/off music only.
Realtime light trajectory preview , while placing the available objects, would also help solving more complex levels where there are too many possible objects locations combinations available without reading the solution file (maybe it could be implemented in an "easy mode").
Another usefull feature could be the ability to zoom in/out to better see light trajectory when it would extending far away from the default game field limits.
Thanks again for your work.