By 2004, video games were well into their adolescence. The war between Sega and Nintendo that defined the early 1990s was in the rear-view mirror – the PlayStation had knocked both of them off their perch, and Microsoft had released the Xbox. The critical and commercial hits of the day were not cartoon platformers but operatic space shooters (Halo) and anarchic crime games (Grand Theft Auto). There were lots of guns, and most games were embracing increasingly cinematic cutscenes.

Nintendo, meanwhile, had fallen into third place with its Game Cube home console – but it still owned the handheld game market with the Game Boy Advance. Everyone was expecting the next iteration in the Game Boy family. But instead, Nintendo released a strange-looking silver clamshell console that you controlled with a stylus.

The Nintendo DS turns 20 this month. Despite its weird looks and unconventional controls, it was Nintendo’s biggest-ever hit, selling more than 150m units. It catered not just to people who wanted to play Mario on the go, but also to those who had never thought of picking up a video game console before. Intuitive touchscreen controls opened video games up to millions more people than the Game Boy had been able to reach. On the DS, you could play sudoku, language-learning games and raise virtual pets. Many people bought it not for Pokémon but for Dr Kawashima’s Brain Training.

The idea of a dual-screen console had been knocking about at Nintendo for a while. It was an idea that Hiroshi Yamauchi, president of Nintendo from 1949 until 2002, was especially fond of, and he mentioned it often to his successor, Satoru Iwata, and to Shigeru Miyamoto, Nintendo’s creative lead. As Iwata put it: “The demand to make something with two screens had been with us for a while, a persistent source of motivation, to the point where Miyamoto and I basically reverse-engineered the thing.”

Iwata always had confidence in the idea, but the markets and the public met the DS with enormous scepticism. “At first, lots of people were confused,” he remembered. “When we announced, ‘We’re going to release a console that has two screens and a touch panel’, most people must have thought, Nintendo has gone off the deep end.”

In retrospect, the Nintendo DS prepared the world for the iPhone, and for the explosion in touchscreen smartphone gaming that would eventually kill off the whole idea of a handheld games console. We don’t need them any more, now that we have one device that fits in our pockets and can do everything from giving us directions and taking photos to playing games. The DS was a half step between the Game Boy and the smartphone – a device that played games but could also do other things.

I was there for the games, of course. When I bought my DS, nobody knew that it would vastly expand the gaming population. And it had some tremendous games, including plenty of weird and wonderful ones. The DS’s new control method seemed to inspire developers to do all kinds of playful, unexpected things. Touchscreen control was this console’s most lasting innovation, but the dual-screen clamshell of the DS is surprisingly adaptable, and lent itself to a bunch of uses.

Brain Training had you holding the console sideways like a book, writing answers to simple maths and logic questions on the touch-screen. The puzzles in adventure game Another Code had you opening and closing the DS to stamp documents, or angling the screens to reflect off one another to decipher a symbol. In Electroplankton, you draw paths for small musical organisms. There was even a Guitar Hero game that came with a small attachable fretboard and plectrum. In the DS Zelda game Phantom Hourglass you have to shout at a character through the microphone to get them to lower a bridge for you. You could talk to your Nintendog, too.

More than anything, the DS inspired variety. I have a huge collection of DS games ranging from unexpectedly heartbreaking desert-island simulators (Lost in Blue) and the basketball game Mario Hoops 3-on-3 to rhythm games and visual novels (the courageously heartfelt lawyer-drama series Phoenix Wright: Ace Attorney has never been better than it was on the DS). Among its bestsellers were, as you’d expect, New Super Mario Bros and Mario Kart, but also Brain Training, Nintendogs and Professor Layton (a charming puzzle game about an English professor and his child protege). Its catalogue was anything but homogeneous.

The 3DS, released in 2011, was a worthy successor with its own great lineup, but by then smartphones had already dealt a killer blow to the handheld games console, and the industry was becoming more conservative. The kind of wide-ranging, open-ended experimentation that defined the DS catalogue would never be seen again. The DS will be remembered by the world as the console that pioneered touch-screen control – but for me, it’ll always be the console with the most eclectic selection of games ever.

What to play

The most obvious classic DS picks are Mario Kart, Advance Wars: Dual Strike, Nintendogs (don’t @ me) and Animal Crossing: Wild World. But since when have I ever served you what’s obvious?

Osu! Tatakae! Ouendan (called Elite Beat Agents outside Japan), is the perfect encapsulation of this experimental age in handheld game design. It is an interactive musical opera-manga in which you take control of a team of cheerleaders to help people through moments of strife in their lives, soundtracked by massive J-pop tunes. You use the stylus to tap and swipe in time with the music, directing the cheer squad to help a pottery artist rediscover his muse, a school pupil ace his exams and a ghost tell his still-living wife that he loves her. There are carts on eBay for less than £15.

Available on: Nintendo DS
Estimated playtime: 4 of the best hours of your life

What to read

• The Grammy nominees for best video game soundtrack have been announced. They are: Avatar: Frontiers of Pandora; God of War Ragnarök: Valhalla; Marvel’s Spider-Man 2; Star Wars Outlaws; and Wizardry: Proving Grounds of the Mad Overlord. We recently profiled the people behind the music of Star Wars Outlaws in our High Scores video game music column.

• Deadline reports that the stars of Amazon Prime’s excellent Fallout TV adaptation will be joined next season byMacaulay Culkin, as “a crazy-genius type character”.

• Sony and Nintendo announced quarterly financial results this week. Highlights on the PlayStation side: Sony has now sold 65m units of the PS5, and 1.5m of the delightful Astro Bot. On the Nintendo side: it has now sold 146m Switch consoles, which still falls just short of the DS (154m) as Nintendo’s bestselling console ever.

• The next Nintendo console will be backwards-compatible with Switch games, Nintendo’s president, Shuntaro Furukawa, confirmed in a press conference. More details on the new machine are coming before the end of this financial year.

What to click

Question Block

Reader Lewis asks:

“I love playing mobile games of all types, but the one I play the most often is a Puzzle Bobble/Bust-a-Move copycat that I use to mindlessly destress after a long day (I’m on level 5,264). The only issue with these games is the endless onslaught of confusing, long and weird adverts. Do you have any suggestions for solid, well designed, free puzzle games will keep me from doomscrolling?”

Alas, the price for free games on your phone is, almost invariably, horrible ads. My first thought is: do you have a Netflix subscription? It comes with a bunch of smartphone games, some of which are very good puzzlers: Monument Valley, Paper Trail, Arranger, Cut the Rope and a variety of appealingly mindless match-3 and word games.

I also asked the fine people of Bluesky to weigh in, and here are the recommendations they came back with (thank you, everyone): Slice & Dice, Konami’s Pixel Puzzle Collection, Township, Threes, Match Factory! and Twenty. A dev shouted out their game, Vectic Lite, which has ignorable banner ads, alongside another banner-ad-only puzzle game called Nokama. There’s also an independent puzzle games website, Thinky Games, that lets you search its database for recommendations.

If you’ve got a question for Question Block – or anything else to say about the newsletter – hit reply or email us on pushingbuttons@theguardian.com.