No. Super Mario Galaxy is easy, save a few stars.
At most, that would rank you as Good.
A better way to determine how good you are is see how long it takes you to collect all 242. Or 121 if that is way too long.
Kimi wa ne tashika ni ano toki watashi no soba ni ita
Itsudatte itsudatte itsudatte
Sugu yoko de waratteita
Nakushitemo torimodosu kimi wo
I will never leave you