You can get "Welcome Gift" That is packed with 30 heartcoins.
The gift is activated only one time. When you open it, there is no more chance to get free heartcoin.
You can use it to buy some initial powerful weapons, or keep it to get the bunny costume.

Caution : If you already have some heartcoins or used it, please keep your "HeartAccount.txt" File before the Update, and Overwrite the "HeartAccount.txt" File after the update.
The Update would empty "HeartAccount.txt". That will get rid of all of your usage record of heartcoins. So if you don't want that happen, you need to do the job.
Sorry for the inconvenience.