Gardenscapes is similar to Candy Crush in that you have to match a certain number of different pieces to get special bombs which can then either be used on their own or matched with other bombs to blow up larger chunks of the matching field.
You will earn coins as you complete levels and unless you are constantly running out of moves during the levels you should not run out of coins to purchase more moves. If however you do run out of coins you can always buy more as an in-app purchase using real money.
Whenever you finish a level with moves left over, the moves will turn into bombs and blow themselves up automatically and you will earn an extra 50 coins for each explosion on top of the 50 that you get for beating the level. When you finish a level you will also earn one star, you will earn different amounts of coins per level and this is dependant on how you performed but there will always only be one star rewarded per level.
The game also has a social network (the fictional one in the game, not Facebook) which is filled with the different people that you have met throughout the game and as you complete quests more people will be added to your friends list.