Do they generally come with a battery so you can save your progress? I bought one recently and I'm super jazzed to finally getting to play it, but to get to the Wily Tower you have to beat Mega Mans 1-3 first and I'd rather not have to do it in one epic sitting, especially since Mega Man 1 is one of the hardest Mega Mans for me.
I unintentionally got a pirate copy of Mario & Luigi (oh my naivety in thinking that a copy of the game from China could possibly be legit) and it came with a battery, so are the chances good?