Star you can earn on your save file:
1st Star: Beat the game (Warp Cannons aloud)
2nd Star: In World 9 collect all 24 Star coins
3rd Star: Beat the normal levels in SMBW (Secret goal not required)
4th Star: In the first 8 worlds collect all 207 Star coins
5th Star: Use all the Warp cannons, find all secret goals and win every level
Sparkly Star: Obtain all 5 Stars above without the Luigi Block appearing (don't die 8 times in a row on a level)
Alternative endings
1st ending: Beat the game once to hear the Princess say 'Did I ever tell you about the Secret World?
2nd ending: Beat SMBW a second time and the Princess will say 'Oh Mario, tell me about your adventure again'
Beating the game also unlocks world 9 To unlock the levels in world 9 you have to find all the stars in each level to progress.
You can now save the game anytime replacing the Quick save option.
All mushroom houses in worlds 1 to 8 will reappear - collect all Star coins in worlds 1 to 9 visit all the warp cannons and they'll stay for good. (all videos have to be unlocked and you need all 5 stars)