If you’re an indie game developer, you’re well aware of the challenges you face. With great ideas, good promotion, and a generous helping of luck, you could launch the next “Minecraft”—and take home a multi-million-dollar (or even billion-dollar) payday. But as anyone who’s actually tried to build a game knows, even modest success can prove elusive. That’s why it’s always interesting to see a list of which indie games are selling particularly well. At this year’s Game Developers Conference, Nintendo decided to share a list of bestselling indies for the Switch console. If you build and/or play games, you’ll no doubt recognize a few of these: Unfortunately, Nintendo didn’t break out exact unit sales, making these games difficult to definitively rank. But the trends are clear: retro is in (along with side-scrollers), and not just because retro is cool: If you have relatively limited resources, crafting a side-scroller throwback to the good ol’ “Metroidvania” days of the late 1980s/early 1990s (for example) is more feasible than trying something ultra-modern and complex. But Nintendo has also instituted something of a bottleneck when it comes to submitting indie games to the platform. Registering to become a Nintendo developer is a straightforward process via a website portal. Beyond that, however, you have to actively bring the game to Nintendo’s attention by reaching out to them. A year ago, Damon Baker, Nintendo of America’s head of partner management, told Gamasutra about the company’s philosophy behind indie game submissions. “We are being very selective about who we’re letting into the development environment, and through our portal,” he said. “Whereas with the Wii U and 3DS, we opened that up to everybody. I think our mentality was to cast big net, [but] you’d never know when the next great piece of content was coming, or where it was gonna come from, or where it was going to permeate.” He added at the time: “We’re just telling publishers and developers to reach out to us if they haven’t heard [from] us already.” As a platform, the Switch has attracted constant developer attention since its release (at least according to annual surveys conducted by the Game Developers Conference). For those who want to build games for it, familiarity with standard-issue tools and platforms such as Unity is a must. And focusing on a throwback/retro aesthetic can’t hurt your eventual chances of creating a winning game, either—provided Nintendo returns your email.