I love the principle of the game. A lot.
But there could be some improvements.
1. It is confusing to keep all the clues in mind, so it would be great to indicate which ones have already been solved.
2. I would like to take notes in cells, e.g. if there are two options, I would like to take a note of that.
3. Losing a star for synonyms is annoying, e.g. gravitation/gravity
4. Hints should be hints, not solutions. It’s annoying if you make your third mistake in the last cell, then watch a video and than don’t even see the correct solution. Why not give the first letter instead?
5. Not a flaw, but a suggestion: daily challenges, a more interactive mode such as a leaderboard or the option to play with others would be nice to have.