Nelly Cootalot has gorgeous backgrounds, great animations, and a unique art style not seen anywhere else. I can't think of any flaws in the art at all.
Sound effects are minimal, however the game has a wonderful, fitting soundtrack by the always brilliant Mark Lovegrove.
A rather standard point and click game. The interface is good and functional, and the puzzles all range from easy to medium difficulty. Even though I'm a fan of harder games, the charm of this game is enough for me to keep playing.