Hearthstone is completely different than any other card game you have ever played before. It is not a magic and that is a very good point.
Magic is the most complex card game ever made, but at the same time is a TGC and this is a very sad point. If you dont spend one or two cars in one deck you cant be a competitive player. 1 Turn games in legacy are pathetic and spoil the soul of a good card battle.
Why does hearthstone deserve a 10? very simple! First it is easy to learn the game, you wont take months learning rules, combos and decks strategies. Second it is hard to master, yeah if you have played for a long time this game you can simply destroy any rookie in your way, at the same time a competitive match is very exciting. Third you can have your cars and dont have to sell them to buy card packs, money doesnt affect too much this game. if you are poor or dont want to spend a lot of money with a card game hearthstone is your game. You will never lose a game because someone has a full legendary deck, it will simply wont work. Believe in me when a say not being a TGC is a great point to play this card game!
Some players will complain about RNG effects affecting so much the gameplay but dont think this is a bad point. You will get mad in some games, but you will get vey happy in others games. Random effects give more thrill to the battle. You have to be dedicated, smart, creative and lucky. these are the package to sucess in this game and real life. you must not complain about luck, use it wisely and yeah! you will "get lucky" haha.
The art work, expansions, card lines make the game fun and deep, be sure if you like card games to try this one, you wont get disappointed.