Less is more. That's the advice Nintendo's Takashi Tezuka, who's worked on dozens of Super Mario games since 1985's Super Mario Bros., offered when I asked him what makes a good Mario level.

"In Mario games, each one has 60 to 80 courses, and each course needs to have its own unique defining element," Tezuka said in an interview with Polygon. "If you build too many elements into every course, they start to feel the same. That's something you need to be careful of.

"To me, the real trick is limiting [the number of] course objects. That's what makes it really special."

When I played Super Mario Maker on a Wii U at Nintendo's E3 booth this week, a variety of internally-developed levels were available. One that stood out was named "Not Scary if You Keep Running." True to its name, all one had to do to complete the level was hold right on the D-pad and run. But along the way, Mario bounced on Boos, music note blocks and one very important P-block, turning a row of coins into a walkable platform. It was a rush, but it was also very simple, and, per Tezuka's advice, used only a few elements from Super Mario Maker's rich level editor.

That level also stood out to Tezuka, he said, after I'd mentioned it.

"People try to have a tendency to cram every cool feature into one," Tezuka said, explaining that the sample levels playable at E3 were primarily made not by professional level designers, but artists, programmers and members of Nintendo's Treehouse team.

"The role of Super Mario Maker isn't trying to recreate a course or compete against something that you would purchase created by a professional level designer," Tezuka said, "It's trying to do what you haven't seen in a game and make it your own, to have fun."

That said, Tezuka said he thinks that Super Mario Maker players will learn valuable level design skills by copying existing levels and trying to edit them and improve upon them.

"I think it's great to find something that you think that works really well, copy it, mimic it and try to think of ways you can improve it," he said. "It's a good way to learn."

Just one warning though: A Nintendo rep told us at E3 that if you download someone else's level from Super Mario Maker, you won't be able to re-upload your edits to that level.

Another source of inspiration and guidance for budding Mario level designers, Tezuka said, is the book that Nintendo is shipping with every copy of Super Mario Maker. The book features some classic Mario artwork and reproductions of original design documents for Super Mario Bros., but it also contains hints and ideas for level design.

"I think the book that comes with the game will help people hone their skills and learn techniques they can add to their own courses," Tezuka said. "If we were to name this book, we would call it 'The Seeds of Super Mario Maker.' We give you all the basics to make something great."

But the resource that Super Mario Maker fans should really turn to — something that many players would normally never do — is ... the game's digital manual.

"We're actually really, really proud of our e-manual because we found that players get stuck in creating a course, they can look to it for inspiration again and again in getting them on their way," said Super Mario Maker game director Yosuke Oshino.

In addition to tips and tutorials that explain the best practices of Mario level creation, the e-manual also includes brief videos that players can watch. Those short clips teach the basics, like where players should place coins and how to build objects for Mario to jump on or over. There's even an advice column included in the digital manual.

"E-manuals aren't known for being the most interesting reading," Tezuka said. "We don't know people who read them, but we think you can read the Super Mario Maker manual all day. It's going to be packed with all sorts of interesting content."

"With a browser-based e-manual, we can make anything we want," Oshino said. "We have a lot more creative freedom to design [compared to a text-based manual]. We made it so that it's something enjoyable all on its own."