This is a compilation of the following games ported from the GBA to the NDS:
There are two ways to play the game. One is to do the “Easy Scenario” where you start at Mega Man Zero and then play straight through all four games without a break. The other mode “Title Select” allows you to choose which of the four games to play. Oddly enough, you cannot independently select a difficulty mode. The scenario mode is always on “Easy” and the title select is always on “Normal.”
While I like the idea of being able to play through all four games in sequence, I would have preferred that to not be linked to the difficulty level. What if someone just wants to play Mega Man Zero 3, for example, but he wants to play on “Easy” mode? He’d have to play through the first two games first, and since there is only one save, once he plays through Zero 3 he can’t easily jump back there again later. Overall, this seems to me to be a very odd way of going about it.
“Title Select” mode uses the standard save slots that the original GBA games have. So how many slots you have depends on the game. These saves are separate from the scenario mode save.