Sentinels of the Multiverse is a cooperative card game (though playable solo) that pits a team of heroes against a dastardly villain. Gameplay is pretty straightforward as each player controls a hero and on their turn chooses their actions. While every player plays a hero, the villain is controlled by an automatic process of flipping cards which may give the villain new weapons and minions, put innocents in danger, or progress in some evil scheme. The heroes have to beat the villain down and foil his/her/its schemes. Along the way, heroes may fall (but can still take limited actions to aid their fellow heroes) or the villain may complete the scheme and win the game. Generally, the game favors the heroes but certain heroes may be more complicated and thus harder to use and some villains have more difficult and complex scenarios so even experienced players can face a challenge.
The cards are generally of quality stock and bright and colorful. Many cards reference famous comic book events, covers, and characters (with quite a few heroes and villains being obvious expies of famous (and copyrighted) characters). With that said, the artwork is sometimes rough and often reminiscent of the 90s era of comics. Plenty of the art is viewable online so if that's a major concern, take a look before buying. Personally, I find the art serviceable with some excellent images scattered throughout.
Overall, Sentinels of the Multiverse is a must-have for superhero fanatics and those looking for an intense, varied cooperative play experience.