Ultimate Block Party (titled Kollon (ころん) in Japan, Koloomn in Europe) is a puzzle game series where blocks must be cleared. Every so often new rows of blocks will push up the current ones. Not clearing enough within a set time limit will force the blocks to the top of the screen, where the player will lose. Blocks can be cleared if at least four blocks of the same color are touching. The speed of new rows will increase as the game is played longer. The blocks which get cleared will result in the blocks above falling down. The game offers several different modes including a multiplayer and arcade mode. Games in the franchise have been released for the arcade, PSP, and mobile phone (EZweb, Yahoo! Keitai (Yahoo!ケータイ)). A second PSP Kollon game, titled Korokoro Kollon (コロコロころん) was released in Japan on June 22, 2006.