Rhythm & Difficulty

I've always loved rhythm games. The feeling of improvement, of flowing with the music and reacting quickly, of reaching the point where you're reacting more by instinct than by thought; it's a major part of what I enjoy about playing games distilled to its very essence.

For a long time I've internally coined rhythm games as "pure gameplay" games. Their presentations are often abstract, with only the smallest amount of context provided, stripped of narrative, absent any major systems aside from notes to hit and the points they award. There's just a song and your skill. Pick a tune, press play, and jam. Repeat until the walls mimic the scrolling of the notes (if you know, you know).

 Difficulty Levels

There has been a recent spate of new rhythm game releases which got my designer-brain thinking about what makes them so endlessly enjoyable, and to such a wide variety of players. I believe a major reason is the massive amount of control rhythm games allow over their difficulty. While most games have a handful of difficulty options, and some have no choice at all (insert the discourse about Soulsborne games here), rhythm games often have a dozen difficulties on the low end, with the occasional game providing 100 or more (such as Flash Flash Revolution).

Difficulty selection in Muse Dash

On top of this, many rhythm games split difficulty across two types which I'll call "speed difficulty" and "feature difficulty":

• Speed Difficulty is the rate or density of the notes you have to hit. This is usually represented as a raw number
  
• Feature Difficulty represents new features or patterns that you only see when this difficulty is increased. A single song may have several difficulty selections, often specifically to increase feature difficulty in addition to higher speed

 A good example of feature difficulty can be found in Guitar Hero, where higher difficulties will start using more of the guitar's buttons, eventually requiring the player to move their hand quickly between the simulated frets. Other games may introduce things like obstacles or more complicated patterns of notes.

The same Guitar Hero song on different difficulties

Player Agency

 The result of this huge array of difficulty options means that a player is always able to find a difficulty that matches their skill or current mood. You can continuously calibrate instead of picking a difficulty before you've ever played the game (and sometimes being stuck with it).

You may feel differently, but even when a traditionally linear game gives me the option to change the difficulty during a big campaign, I feel I've already made a commitment to the difficulty and it's almost "giving up" to lower it later on. It's tough to get a sense of whether you've hit a difficulty spike, or if you really should adjust the entire game to suit your skill level.

Difficulty description at the start of Doom Eternal

In a rhythm game, you can never become hard stuck or disenfranchised with the difficulty because failing one song is never a blocker to choosing another song and practicing elsewhere. This encourages and enables rapid improvement as you can always find the sweet spot between "so easy I'm bored" and "so difficult I'm frustrated." This improvement is deeply satisfying for players looking to express skill in games, myself included.

A Rare System

Curiously, this type of system seems to be rare outside of rhythm games. I believe this is due to a number of limitations:

• It works best if you regularly return to a hub area, where the next activity is chosen and difficulty can be selected
• It requires a number of ways to adjust difficulty in an escalating and, most critically, skillful way. Gating by a character's gear/level won't result in the same feeling of player improvement
• The game should introduce new mechanics or behaviors for more difficult versions of the same content
• In general this can be a very content-heavy strategy (rhythm games often have dozens or hundreds of songs)
  

More linear games such as The Last of Us aren't as suited to
this level of difficulty selection

 Other Genres

Despite these limitations, I'd love to see such systems spread to other genres. I've seen several that are similar, such as Heat in Hades, Mythic Dungeons in World of Warcraft, or the wide range of levels and star challenges found in Overcooked. I'd love to see these taken further. Imagine a strategy game where each mission could have a varied number of enemy units, available resources, army limits, or other difficulty adjustments. I'd love to see an action game that is nothing but a series of smaller fights, each one of a wide range of difficulties based on the techniques and skills needed to clear them. 

Either way, I'll have plenty of rhythm games to keep me busy. Jam on.