List with unique gameplay features of Hearts online game:

1. Hearts game that has the ability to play with friends or against the computer.
2. Hearts online game that has multiplayer games that players can play with friends from all over the world.
3. Hearts game that has an ability to play with an AI opponent.
4. Hearts online game has an ability to watch the screen of your opponent during the game.
5. Hearts online game with the ability to chat with your opponents during the game.
6. Hearts game that has a variation of game modes to play with different players.
7. Hearts online game that has the ability to use different avatars.
8. Hearts game with a chat option that is available to be used during the game.
9. Hearts online game with the ability to play against AI players from different levels.
10. Hearts online game that has the ability to unlock levels.
11. Hearts online game that has the ability to get a new avatar after winning the game.
12. Hearts online game that has the ability to get a reward after reaching a certain level.
13. Hearts online game with the ability to get a reward after winning a game.
14. Hearts online game that has the ability to unlock the new avatars by winning the game.