How to unlock characters and stages in Super Smash Land?

Solution 1:

Megaman is unlocked after beating Arcade as all 4 starting characters.

Vaporeon appears randomly on the Saffron City stage, defeat her when she shows during versus, then finish the match to unlock her. A method to get this to work was shown in a youtube video in which you could start a versus match with 99 lives, let idle for a while before Vaporeon shows, then after defeating her you can suicide your remaining lives to end the match.

Solution 2:

You get endless mode when you have all people. It's kinda like all-star mode in brawl/melee

Solution 3:

Endless Mode is unlocked when you have both Mega Man and Vaporeon.