I thought Circle of the Moon was higher than a D+, but certainly not an A. The attack system (DSS, I think it was called?) seemed interesting in theory, but in practice, most of the more readily available attacks were unfortunately pretty weak (and in order to get the good ones, it seemed like you had to attack the same enemy over and over again, which became tedious very quickly). I also did not like the fact that in many of the areas, it seemed as though you had to spend time leveling up to get anywhere. Still, it was the best handheld Castlevania of its time, and the music was a great selection of tunes from Castlevanias past, so I'd probably give it a solid B.
If there's any grade I'd disagree with the critic on, it's definitely the Harmony of Dissonance one. I'd give that game a much lower grade, probably a C or so, due to rather dull gameplay and terrible music.
That said, the best Castlevania games are nothing short of stellar, and I'm looking forward to the Critic's review of the Dracula X Chronicles for PSP.