The download button opens the iTunes App Store, where you
may continue the download process. You must have iTunes installed with an
active iTunes account in order to download and install the software. This
download may not be available in some countries.
From Allen Luo:
Random colored Easter Eggs fill the game board on the screen. Players tap on groups of 2 or more adjacent matching eggs to collect them. New random eggs drop down so the board is always full. As the game goes on, eggs will start appearing with numbers on them. The numbered eggs must be matched in a group at least as big as the number (3, 4, or 5, instead of the usual 2). Over time, the numbers get higher and appear more frequently, and the game ends when there are no more possible matches on the board.