Shovel Knight was a game funded on Kickstarter and one of the true success stories to emerge from the platform. Carrying-on the lineage of classic platformers like Super Mario World, Mega Man, and CastleVania, Shovel Knight didn't reinvent the wheel but it might have perfected it.
Of course, in the world of gaming it comes as blasphemy to say anything is better than those that pioneered the way, those that people hold the most nostalgia for, but the reality is that Shovel Knight combined the best elements of all of those classic games to make the perfect action platformer. Even though it is an amalgamation of those games, taking the world map, inventory, and combat from NES classics, Shovel Knight was a success because it has a personality of its own.
With whimsical characters, fairytale setting, and flawless mechanics, Shovel Knight did was so few other modern platformers were able to achieve: originality and peerless quality. Available on pretty much every platform imaginable, there's no excuse not to play Shovel Knight. Personally I played it on the PS Vita, where it feels right at home. Furthermore, Yacht Club Games, developer of Shovel Knight, has released two full-length DLC's, the most recent being a brand new game from head-to-toe, and there's more to come. Oh, and all of it has been free if you already own the game. That's fan service like no other. So, what are you waiting for?