There are way too many "retro-style" games that aren't anything like old games, which only seem to be "retro" style because their creators are pretentious and/or lazy.
Shovel Knight is not one of those games.
It looks perfect. It sounds perfect. It, shockingly enough in this world of "hey retro means really hard right?" games, PLAYS perfect. It gets tough at points, tough enough for you to die at the same point five times, tough enough for you to scream out loud, and yet manages to get it right to the point where you DON'T say the game is bullshit and unfair, because it's not. If you die, you certainly know why, and know what to do next to not die (and then you invariably screw up and die again).
Playing this game makes you feel like a child again. It's a familiar and nostalgic, yet completely new and refreshing experience.
If you grew up playing video games, you HAVE to play this game.
You just do.