The author of the hugely popular Sentinels superhero novels, Van Allen Plexico has published a two-player, heroes-versus-villains card, game based on his on-going series.
The Sentinels Collectible Card Game is available from White Rocket Entertainment in a variety of formats: you can go 'all-in' with the deluxe edition (which gets you everything), or you could purchase either the hero or villain packs, then add in "rare" and "instant" cards to customise your deck.
You can get a taste of the simple rules system here, or dive right in and make a purchase from White Rocket here.
Shipping is free within the US.
Never one to rest on his laurels, Van has also launched his new Avengers Assemble! podcast, spinning out of his long-time involvement at the forefront of Avengers fandom (be it in comics, movies, animation, novels etc) as a founding Jarvis-head of the Avengers Assemble! messageboards and publisher of two collections of essays about the Marvel Comics' superhero group.
It can be found, and subscribed to, on iTunes here.