Here is the full list of all 10 Winx Club: Alfea Butterflix Adventures achievements worth 1,000 gamerscore.
9 keys collected in the first arena
Blue gem key collected in the first arena
Red gem key collected in the first arena
All keys collected in the first arena
6 keys collected in the second arena
Blue gem key collected in the second arena
Red gem key collected in the second arena
All keys collected in the second arena
Key in Potionology room is collected
Key in History of Magic room is collected