Suggestions for future versions: ability to sort cards, ability to upgrade cards using exp/gold, one row to hold cards that are not used in play but retained for either future upgrades or because you are building a deck tailored to your foe, stats showing us the damage dealt/kills/damage taken/deaths/reinforcement points used by each card, upgrade spells using gold/exp - add new spells you can purchase or earn and allow for a 'deck' of spells limiting our choices in each fight.
I agree with many of the comments, this is an easy game. That said, it's really really fun and once I started playing I had to get 100% complete and obtain all of the in game awards. Simple, addictive and fun, perfect for the holiday season.
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 "Monster Legions"){kind=icon}
 "Icy Gifts 2"){kind=icon}