It's such a shame when you see a good game that for whatever reason was just ignored by people, especially when they have the quality of the Mega Man ZX games.
The marketing for both ZX games were poor, Battle Network and Star Force both had epic marketing AND animes!
As a result, they skyrocketed in sales.
The great innovation in the ZX games is being able to play as different "characters", I'm not referring to the male and female protagonists, but in the first ZX game, when you beat a boss, you get their Biometal, which are all based off characters from Mega Man Zero (except Model A, but he's from ZX Advent).
Each Biometal has a different play feel, Model P and F are for taking down hoards of enemies, Model ZX is the all round Biometal, Model H is for much greater mobility, Model L is for... swimming... I guess (but Model L and P are actually fun to use in ZX Advent).
ZX Advent is just even better, your character's Biometal is Model A, which copies boss data when you beat them, so you get to play as the boss, and there are ffive human/reploid bosses who are Mega Men (users of Biometals) and thus, you get all the 5 (excluding Model X and non-canon Model O) Biometals from the first game.
The music is amazing, the gameplay is amazing, the controls are amazing, heck, ZX Advent is my favourite Mega Man game!