Deck building and real-time battery collide in the wonderful Nether Card Kingdom, a free browser game where you draw cards from your deck to fight fantasy battles. Successful medieval battles yield additional cards, which can be added to the deck as is or mashed and upgraded like the demon fusion in Shin Megami Tensei.

Even if you are tired of deck-building games (and there are plenty of games out there trying to get your attention), there is much to appreciate in Nethercard's reasonable yet satisfying way of collecting cards. There are not that many card types, and new cards are introduced gradually. Moreover, each card is fun to use in battle. Three cards at a time are chosen at random, expended (recharged) with energy and placed on the battlefield, at which point the AI takes over and marches its little warriors, archers, and catapults into the enemy.

Special ability cards can be used to heal your own troops or shower the enemy lines with devastating magic, and doing so provides visual and auditory feedback. Simple, but that's the strength of this tactile and engaging action game, and you'll spend more of your day playing it than you might expect.

For more great free experiences, check out our compilation of the best free PC games.