What's cool about SMB is that achievements are REALLY achievements, even completing the light world feels like a great achievement for me.
I don't think there should be an easy version of some achievements, since that would ruin their uniqueness. My suggestions:
"Bandage Boy": get all bandages( is there an achievements for bandages already?..)
"Perfect Boy": get A+ in all levels
"Insane Boy": complete all levels without dying( [D8]maybe not...)
"Nice to meat you": press start game for the first time(just kidding
...dunno guys, actually i think they should not add any achievements until we get the editor.
Then we may see achievements related to levels you published( like in LBP), even though i prefer that achievements refer just to gameplay.