The moon phase styles in MBAA are easily what makes the game interesting and distinguishes it from other fighting games. However, I don't think the moons are completely equal, and I do feel that my favorite moon style, Full, is actually the weakest in game.
Full Moon as a style kind of makes characters play in a more traditional fighting game setting. Melty is mostly known for its extremely freeform chaining system, where everything chains into everything up and down. Full Moon turns that back into the traditional weak->medium->strong chain sequence. Most Melty chars don't have +f on block and hit normals, since their chain options are so numerous, but since Full Moon chars are more restricted, they do have lots of +f on block normals and specials. This actually worked out pretty well and it did a nice job of making up for Full Moon's limited chain options, but Full Moon has a bunch of other weird restrictions that make it the weakest groove.
1)Limited meter. Crescent Moon has the most control over its meter, since c moon chars can heat activate anytime they have over 100%. Heat moon technically has the least control over their meter, but h moon chars make up for it because most of them have 6aa combos, which are longer than combos in other grooves. These combos generate more meter and thus it's very easy for h moon chars to get to Auto Heat more than once per round. For Full Moon, getting to MAX is a once a round thing, as circuit charging isn't really all that useful and practical. F Moon combos are also shorter in general so meter generation is limited.
2)Dodging. F moon is the only groove that cannot ground and air dodge. For ground dodging, it's not really that big of a deal because they're pretty limited in use except for chars that have roll dodges, like Kohaku and Mech. However, not having air dodge is a huge weakness. Air dodges actually aren't used to "dodge" things: they're more used as another jump in the air, as they delay a character's falling momentum. Also important is that they turn your character in the right direction in the air if you were facing the wrong direction. Some characters can even use air dodge as a left/right mixup. F moon chars not having air dodges basically means they all have less mobility compared to other moons.
3)Air dash cancelling. C and H moon can airdash cancel all air normals on block and hit, with a few exceptions. F moon characters can only airdash cancel j.a's. F moon can still do a similar technique for j.b and j.c attacks by doing an IAD cancel, which is cancelling the air normal into a double jump, and then immediately cancelling the double jump into an airdash. However, this requires the F moon character to have a double jump available, so it's more limited compared to C and H.
4)Empty cancelling a attacks. Throughout Melty's history, using EX moves as reversals was always bad because of the ability to cancel the recovery frames of whiffed a attacks into anything. Most notably, you could even cancel a whiffed a attack into a shield. So it was extremely easy to go for a meaty 2a/5a, and just react to superflash and cancel to a shield if opponent did a wakeup super. However, F moon for whatever reason can't cancel whiffed a attacks into shields. So they're more vulnerable to wakeup EX moves than the other grooves.
There are definitely some strong Full Moon characters, like Nero, the Maids, Miyako, and Akiha, but in general the groove is significantly weaker than Crescent and Full.
