Kongai is a really excellent digital collectible card game hosted by Kongregate. The strategy is sufficiently deep so that explaining here wouldn't really be practical but, in short, you'll pit three or five character cards against three or five of an enemy's. You'll then have to balance choosing the right attack for the right situation with knowing when to retreat.
At first, it may seem a little broken, with any attack able to be evaded by switching out the character in play. But when you realize that you can counter that evasion with a devastating attack if you successfully predict it, the game takes on the quality of a game of psychic rock-paper-scissors. It's bizarrely addictive, and really difficult to explain the charms of.
If you're a frequent visitor to Kongregate, you already know a bit about Kongai, in fact, you could say you've been preparing to play it for months. Each week, the site's been offering up new challenges on different games. If you've been religiously completing them like we have, you've already got a stockpile of quite a few cards. It's also a compelling reason to keep going back to the service.
We know, we know, this may not sound like your cup of tea. But please, go give it a whirl. Of course, if you're half as addicted as we are, we'll never see you again.