Try Duelyst!

I found the game Duelyst yesterday and after playing it for most of the afternoon, I'm a big fan.  The game is a mix of trading card game elements mixed with a top down strategy game.  If you like Hearthstone, Advance Wars, and free things you should try this game.  Each game is a battle between two generals that summon minions and use spells to bring the other's health points down to zero.  Generals move around on a grid and summon units around them.  What make Duelyst unique is the units that are summoned are drawn from a deck of cards adding a trading card game layer to grid based battling.

The art in the game is a mixture of pixel art units in front of hand drawn backgrounds.  It makes everything in the game very readable.  The music and sound effects are good at conveying the clash between units on the battlefield.  The game play is where the game really shines though.  Each faction plays differently from a ranger, to a melee monster, to a necromancer.  Every card is readable through gratuitous tool tips.  The game is complex at first and I would suggest running though the games challenge modes to get a hang of unit effects along with some practice rounds against coms to really wrap your head around the game.  Jumping online was a great experience even with just the starter deck.  The game will pair you with someone your level in under a minute in a lot of cases and the chat options are limited to simple emoticons which mitigates trolls.

The game is great for being in the middle of beta.  It's entirely free and gives you a good helping of in game gold at the start for making your own decks.  I've gotten some good cards out of the little booster packs and the game gives you options for purchasing more.  I'll give an update once I build some of my own decks.  Otherwise, Duelyst is free and awesome so check it out.
https://duelyst.com/