To progress to the next stage, three keys are needed. You can unlock the next stage by waiting for free keys, requesting keys from friends, or by purchasing keys with Jewels. To request them from friends, just click on the lock and you will be prompted with a pop up with options on how to open it.
Keys that are sent to you are credited to your account
when you first sign onto Buggle 2, not when you accept the message.
However, an account cannot have more than three keys at any given time,
so if you are maxed out, keys sent by your friends cannot be credited to your account. If you repeatedly request keys from the same friend, you will not receive additional keys.
For example, if you request a key from a friend at 11 o'clock and then to the same friend at 12 o'clock, the amount of keys will remain the same even if your friend accepts your request.
Also,If you closed the Message Center without taking the items (lives, coins, moves) from your friends when you start the game, some of the items will disappear. So please close the Message Center after you have received the items.