Related: Sword Fighters Smash Ultimate Fans Wouldn't Mind Being Added Half the reason Smash Bros. exists is to cross-promote franchises, so adding in established characters from other universes to any project can bring in new fans on both sides of the exchange.
With everyone from Sonic to Snake to Simon Belmont appearing alongside Mario and Link in Smash, it only seemed logical for indie developers to team up as well. It's easy to see, not only in the platform-fighting genre that it helped generate but also the common UI elements that pop up in plenty of indie games. Capcom for a long time, it is Nintendo's Super Smash Bros. franchise that has really sparked the imagination of the mainstream. While giant crossover rosters have existed in games like Marvel vs. For more than six years now, if a game has a roster of guest characters, it's almost a foregone conclusion that the blue armored hero would be among them. Anyone who has played in the indie space since the game's 2014 release will likely be familiar with Yacht Club's strategy to achieve the other part of that goal. They wanted their NES-inspired platform to be a hit and they wanted its star Shovel Knightto be " the next Mario." The first part of this mission is long since achieved, with Shovel Knight: Treasure Trove and its various standalone sequels selling in the millions across a wide range of gaming platforms.
In Jason Schrier's 2017 book Blood, Sweat, and Pixels, Yacht Club Games makes their first game's mission statement very clear.