Usually I don't go for card games like Magic: The gathering because I simply have to devote ages learning the rules, making a good deck, devising strategies etc. But every once in a while I come across a game (like for example this) that does away with all that complexity and just gets down to the basics without much overhead. Encounter is one of them.
Each turn you just pick a line, column, or diagonal, which is composed of 4 characters (there a 4 different skills). Depending on the characters and how many of each there are in your selection you get different attacks, combos and even more combos depending on the powerups you get. It really only takes a couple of turns to figure out most of the game so I think I've written too much already. Try it out!