There is one exception, though -- video games based on rhythm and exercising. Those are straightforward adaptations of real-life physical activities, so their popularity should mirror the popularity of the real activities.
Specifically, they should be least popular during a vulnerable phase, when people's energy levels are in a refractory state. They should catch on during the following restless warm-up phase, when energy levels are back to baseline and people want to do simple exercises to get back into the swing of things, especially if it involves a social setting where they can mix it up with others rather than continue hiding under a pile of blankets. And they should last into the following manic phase, even if they won't be quite so popular because they've already gotten used to the simple-step exercises and now want something more physically demanding, if anything.
What do you know, that's exactly the pattern of popularity across several cycles. And unlike other genres, these two were both highly popular with females as well as males, and were often played in social groups, even in public places.
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The rhythm game genre first hit it big during the manic phase of the late '90s with PaRappa the Rapper and more importantly Dance Dance Revolution, which involves moving your feet onto various positions of a pressure-sensitive dance mat according to the timed sequence of moves shown on the screen, as music blares in the background.
During the vulnerable phase of the early 2000s, the genre nearly vanished. Only two titles are even remotely familiar to a non-gamer like me -- Donkey Konga and Samba de Amigo, which use special percussion controllers. Neither was a mega-hit like Dance Dance Revolution, though. The DDR series itself saw only a couple releases during this five-year phase. Everyone was in too emo of a mood, and their energy levels were negative.
Then all of a sudden in 2005, when the restless warm-up phase began, a mass phenomenon of rhythm games took over the video game world, lasting through the final year of the phase in 2009. Most notable were the Guitar Hero and Rock Band series, which used all manner of special controllers shaped and played like real guitars, drums, and so on. The games test the player's rhythm by having them press various buttons, use the whammy bar, etc., according to the timed sequence on the screen, as the song plays.
Dance games also saw a revival with the Just Dance series in 2009, not to mention a flood of releases from the DDR series.
These instrumental games were so popular that you could find groups of people playing them together in public nightlife places like bars. They weren't just for teenagers playing with a group of friends inside their home.
As the manic phase began in 2010, the instrumental rhythm games were still popular, although less so than during their restless phase peak. The dance games became more popular, as the Dance Central series joined Just Dance in 2010 (plus more DDR games). Perhaps people had become comfortable with simpler rhythmic activities only involving the hands, like Guitar Hero, and wanted to move onto whole-body rhythms now.
However, when energy levels began crashing in 2015 with the arrival of the vulnerable phase, the rhythm genre nearly vanished again, as in the early 2000s. In 2015, the last major installments in both the Rock Band and Guitar Hero series were flops, and they haven't bothered with either series since.
Similarly, Just Dance stopped receiving numbered titles after 4 in 2012, and stopped receiving new system titles after the one for Wii U in 2014. The Nintendo Switch system came out in 2017, but did not get a dedicated "Just Dance Switch". Now they're just yearly updates with more topical songs. The Dance Central series did not last into the vulnerable phase at all -- its four games were released from 2010-'14, entirely within the manic phase. (In 2019, they did make another for a virtual reality system that no one owns.) And the DDR series only saw a couple releases, just like during the early 2000s.
Now that the restless warm-up phase has begun again in 2020, this genre is ripe for revival. TikTok has already shown the (re-)emergence of dance fever, and the rhythm genre hit its peak in mobile games during the last restless phase (the Tap Tap series of the late 2000s). As for home consoles, I have no idea whether kids born after 2004 (and who have no experience with the last wave of instrumental games) would go for the physical instrument approach. But why wouldn't they? And the older Millennials could fuel their late 2000s nostalgia by having mock instruments to play along with -- akin to the nostalgic fitness craze of "adult kickball" in the late 2000s among late 20-somethings.
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Exercise games show the same pattern over time. The Power Pad for the original Nintendo (late '80s vulnerable phase), and the only game anyone played with it, World Class Track Meet, are not exercise games because they don't involve sustained activity. It was not a hit in any case, but I did know one friend who had it. It was basically 10 seconds of furious running in place on the pressure-sensitive mat, then the event was over; repeat a few more times, then turn the game off. Not much exercise. And there was no rhythm to the motions, so it was not a rhythm game either.
Dance is a kind of exercise, so Dance Dance Revolution also made the exercise genre popular during the late '90s manic phase.
Then nothing during the early 2000s vulnerable phase, when energy levels plummeted into a refractory state.
It wasn't until 2005 -- when else? -- that the genre came back to life, with EyeToy: Kinetic. The motion-sensitive camera used for the game had already been released in 2003, so why didn't they do the obvious and make a fitness game for it at launch? Because people didn't feel like exercising in '03 and '04, being mired in a refractory state. Suddenly in 2005, their energy levels were back to baseline, and they felt like moving around more.
By far the most popular examples of the genre, though, were from the Nintendo Wii, whose pack-in game was Wii Sports that had players using motion-sensitive controllers to simulate tennis and other sports. The Wii Fit from 2007 included its own balance board to track the player's center of gravity, and became one of the best-selling games not to be included with a console. Its sequel in 2009, Wii Fit Plus, was also a mega-hit.
The genre lasted through the early 2010s manic phase, albeit to a lesser extent than before (Wii Fit U; Nike+ Kinect Training; Zombies, Run!). People had become used to simple exercises, and felt successfully awakened from their early 2000s hibernation.
By the time the next vulnerable phase struck from 2015-'19, the whole motion-sensitive mode of play was over. Energy levels crashed into a refractory state all over again, and people went back into hibernation for the first time in 15 years.
But as with the rhythm games, now that 2020 has seen the beginning of another restless warm-up phase, it's the perfect time for exercise games to make a comeback. There's novelty value for the younger kids, and nostalgia value for the older Millennials, in playing an exercise game with some device that is motion- or pressure-sensitive.
And it would fit in well with the quarantine atmosphere, where people are afraid of getting bed sores from being holed up indoors all day long for months on end. That would re-create the social setting of the original Wii games, where parents and children would play them at the same time in the home.
Who knows exactly what form the revivals of rhythm and exercise games will take, but the demand for them will be shooting through the roof now that people are restless again.