Here is the full list of all 19 Bubble Bobble 4 Friends: The Baron's Workshop achievements.
Collected EXTEND Bubbles in all areas on Normal Mode.
Watched Ending.
Cleared Bonner's Castle.
Cleared Cosmic Canopy.
Cleared Toyland Terminal.
Cleared Bedside Bonanza.
Cleared Bookshelf Forest.
Obtained all available achievementss.
Cleared Bookshelf Forest on Hard Mode.
Cleared Bedside Bonanza on Hard Mode.
Cleared Toyland Terminal on Hard Mode.
Cleared Cosmic Canopy on Hard Mode.
Cleared Bonner's Castle on Hard Mode.
Watched Ending (Hard).
Collected EXTEND Bubbles in all areas on Hard Mode.
Earned 3★ in all areas on Normal Mode.
Earned 3★ in all areas on Hard Mode.
Cleared Arcade of Memories.
Cleared Arcade of the Future.