The puzzles were great! The level progression felt smooth, each level being more challenging than the last without jumping too high in difficulty. Several times I had to stop and think about the best way to complete a level, but I never felt lost or unable to continue. Your hint system was really well done, providing direction without giving away the answer, and the inclusion of a colorblind mode and the ability to reread tutorials was a lovely touch.
The one thing I would suggest would be possibly adding a trigger warning about depression on the game page. The story was really well done, but I did find myself tearing up a couple of times because the emotions were hitting close to home and had to take a couple of moments to center myself before continuing.
All in all, this was a really solid game and you did a great job with it.