Heavily influenced by the likes of the NES action-platformers Kirby and Megaman, Yacht Club's Shovel Knight is another of those great homages to nostalgic game design by improving the old ideas with the same aesthetic, while adding some of the lessons of modern game design to bolster the playability.
The gameplay is dumbed down to what you'd expect: you have a shovel so you can smack thing to the side or moving downwards; then there are special items that do different things; and you collect coins and treasure and blah blah blah; all set around umpteen hundred insta-kill pits and spikes that will eventually piss you off.
Granted, the game has a more clever penalty for dying rather than a "lives" system -- each time you die you lose a significant portion of your cash with an opportunity to get it back after your money evolves into Pouch-a-mon, replete with wings to aimlessly flutter about until the player returns to casually kidnap it. (Although these opportunities are sometimes hindered by straight-up impossible areas to get your money back; for instance when they are literally inside spikes.)
The sound and visuals are in good taste, but what shines most about the game is its humor and dialogue: there is no obnoxious assistant to annoy you, just a lot of colorful characters with distinct personalities that really help the game's tone balance between campy "epicness" and lighthearted fun.
Another pleasant surprise is that the main story isn't even shallow: there are these short and perfectly vague dream sequences to demonstrate the relationship between Shovel Knight and Shield Knight in a kind of profound way; making the story's conclusion (before and after the main credits) pretty touching.
The game fortifies itself neatly. Shovel Knight is one of those titles that the developers built with love in order to concisely maximize its potential. Yet I still wish they did more with it... Not that I'm saying that I have any further ideas to implement to the game,but I do wish they toned down the insta-kill objects in the latter half of the campaign.
Other notes:
The alternate campaigns Plague Of Shadows and Specter Of Torment would periodically release as expansion packs that were distributed (unusually) for free. The games would be the same length of the original game with different gameplay and level design, as the new player-characters would have completely different abilities.