This is NOT a free-2-play game.
It's a DEMO of a game. You find the exact same limitations in demos as the 'free version' of this game places on you.
To put it bluntly, you are not going to get more time out of this product than you are from a demo of any other game UNLESS you start buying boosters.
The question then comes, of course, is it worth it to buy boosters?
For me, looking at prices and taking my experiences while trying out the mislabeled DEMO, the answer became a resounding NO.
Doing the story missions (which I did to get every unlock possible in the demo) was somewhat ok. A bit repetitve at times, due to the limitations of the game, but at least the battles were somewhat balanced.
Ability to get cards for free seemed limited to the few you got in the limited amount of solo-play missions available. The only currency in the game is hard cash, and it's not something you can 'earn' by playing (not in any games I tried at least), but purely something you pay to get boosters.
Most of the time when I queued up for online battles against other players, it told me that nobody was available to play against. So I had to alt-tab and do random stuff in a web-browser while trying to even GET games going online against other players.
Any of the battles I tried against other players were horribly horribly mismatched. There was no way the deck I was supplied with as a 'freebie'(or demo player) would compete with the decks of people I met (every one of the ones I met seemed to have paid and played for a while, given their levels and cards).
Randomization also have a huge effect on battles, meaning what initially looked like a balanced battle (as the ones I encountered in the solo missions) can turn onesided very quickly by a combination of cards gotten and mana orb placement. Battles that are already onesided can become extremely pointless beyond hope because of this too (like where my level 3 drake was put up against a level 30 drake by the matchmaking).
Unless you are planning to spend ALOT of money over a period of time to buy boosters as time goes by, steer clear of this one. The variety also seemed close to non-existent in the games I played, despite meeting levels and drakes of different types.
The poor balance, non-varietyof battles, lack of ability to progress without paying for it (coupled with the prices per time you actually consider if you should purchase something) ultimately turned me off from the game once I found out that I had exhausted the demo of its potential in a matter of 4 hours...
Some cute ideas, but ultimately flawed in execution on how they go about trying to handle the 'distribution model'.