I finally did it, I just got all the star coins in World 9 of New Super Mario Brothers for the Nintendo Wii! (Wow was level 9-7 hard!!!)
The game said something like "Congratulations, you've done everything there is to do!"... But knowing Nintendo, I am skeptical. Without spoiling it, is there anything left for me to do, or have I really maxed out the game? (If there is some hidden thing to do, a hint would be much more appreciated than a direct explanation of what the hidden thing is)
FYI, My save game icon does have 5 stars on it.