So, I played all the available stages, earned all the achievements, and yet I have a kinda yellow character on the third character page still locked. Is the means to unlock that one already implemented in the game, or is that something to expect with the full launch?

Also, there's a few things that can be found on the world map, but don't do anything when zoomed in on like the others. Are these just for comedic effect, or will they get a purpose as well?