One sudden day, BT21 received a letter and an album filled with their cherished memories. Join BT21 characters to solve the puzzles, gather happy memories and complete the album! #Get ready for exhilarating Popping Match-3 puzzle! Match the cute blocks to make puzzle go pop! When you gather three or more blocks, they'll burst with a satisfying pop! Create various power-ups and clear puzzle games for more excitement! #Let's collect UNIVERSTAR BT21’s episodes! Collect every puzzle piece by clearing the puzzle stages and unlock unique episodes of the UNIVERSTAR BT21! Collect all the puzzle pieces and enjoy the UNIVERSTAR BT21 episode album! You can also leave your memories by photo memos in the collected episodes. #Exciting survival mode! Experience the heart-racing survival mode, where only the strongest survive till the end! Breath-taking competition with ten players, play it in a friendly match with your club members to prove your skills and show off you...