At the very least it's one of the most fun card games ever made, the mechanics are really solid, and there's a huge variety of builds you can make.
But it's so much more, this is one of the best games to have come out in the recent years if not ever. The work that went into it, the creativity, the plot, the art, it's all great. It never stops surprising you. This is a must play, and try to go as blind as possible