Here is the full list of all 10 COLLECTION of SaGa FINAL FANTASY LEGEND achievements.
Viewed the title screen.
First played FINAL FANTASY LEGEND. (English or Japanese)
First played FINAL FANTASY LEGEND II. (English or Japanese)
First played FINAL FANTASY LEGEND III. (English or Japanese)
Completed FINAL FANTASY LEGEND. (English or Japanese)
Completed FINAL FANTASY LEGEND II. (English or Japanese)
Completed FINAL FANTASY LEGEND III. (English or Japanese)
Completed all FINAL FANTASY LEGEND titles. (English or Japanese)
Viewed the options menu.
Changed game speed settings.