It's a nicely designed game. The biggest flaw is in the business practice 
of the game. Cards are not free, you have to pay for booster packs. You can 
get free boosters and starter decks by completing tasks, but you can only 
get around 2 boosters if you play nonstop in a day. This is a bad move 
because, players must pay to win. If all the cards were free then players 
could test decks with access to all cards, and see which combinations work, 
which would then allow them to buy the physical copy and play in real life 
with others. You can however turn your physical copies into digital copies. 
That's a plus.