beatmania is a popular Rhythm Game developed by Konami as a part of their Bemani games. Considered by many to be one of the forerunners of the modern music game. Of course when they realized how popular the arcade version was, Konami would milk the genre for all its worth with spin-offs (involving dance, drumming, smacking colored buttons, and slapping a grid of buttons), and an endless assortment of Mission Pack Sequels and reboots.Originally described as being a "DJ simulator" (which actually did make sense, given that it had a more hip-hop/house-oriented soundtrack in earlier installments), with what the game has evolved into since the dawn of the 21st century (with almost every genre of electronic music represented, especially if it's hardcore), its anything but.The basic game is simple, players are armed with a 5-key piano-styled keyboard and turntable, and must press keys or scratch the turntable when notes cascade down the screen corresponding to them. This fills up a Groove Gauge; if the gauge finishes above a certain threshold, you pass, it's just that simple. But, when you look at harder songs though, it's also anything but.There have been three major incarnations of the game:
beatmania (or "5-key" beatmania), the original series. First released in 1997, lasting with new versions until "THE FINAL" in 2002, where the aging series (it used the exact same hardware for its entire life) was finally discontinued in favor of...
beatmania IIDX, first released in 1999 as a spin-off, but becoming the primary series in 2002. Kept the same basic gameplay, but added two additional keys to the control array (for a total of 7), a fancier cabinet (with more lights, more effectors, a widescreen monitor, turntables on opposite ends, an LED marquee, and a bass platform), and a difficulty curve that keeps on getting worse every year. What'd you expect when its now on its 21st version?!
beatmania III, a failed attempt to remake the 5-key series using more modern hardware, with higher quality graphics and sound, more effectors, more speakers, effector pedals (which could also be used in special charts), save data on floppy disks, and more. It didn't last long, however, only a few years (it did get its own "THE FINAL" as well).
Games in the "5-key" beatmania and beatmania III series:
All entries are arcade releases unless otherwise noted.
The PS2 port is the last home IIDX port, and is on two discs: Disc 1 is the usual set of songs new as of EMPRESS and some revival songs, and Disc 2, PREMIUM BEST, is a collection of revival songs throughout the entire series.
beatmania IIDX 17 SIRIUS (2009)
First game to have crossover unlocks that require you to play other BEMANI games to unlock them on IIDX.
In the 5-key series and early IIDX games, a rapper-like voice cheers you on when you insert coins or select a song.
Starting with IIDX RED, a voice calls out the folder you open during the song select. Later versions let you choose other announcers, often Bemani vocalists like Kanako Hoshino and SUPER STAR MITSURU.
In tricoro, a robotic female voice can be heard in the card entry, mode select, and result screens, instructing you to insert your e-Amusement pass and select a mode, as well as thanking you for playing at the end of every round.
Artifact Title: Inverted for IIDX: the game was originally produced in two different styles of arcade cabinets, the now rare "standard" cabinet, and a "deluxe" cabinet. On the standard cabinet, the game was known as "beatmania II", but the Deluxe cabinets carried the title "beatmania IIDX" on its artwork and software instead. Later on, the standard cabinet was discontinued, leaving only the deluxe one. At this point, "beatmania IIDX" became the official name of the series
Although, a few errant generic videos (primarily, the Cyber Beat Nation one from 3rd Mix), still contain references to "beatmania II" in them.
Ascended Glitch: The song "GAMBOL" was notorious for an infamous bug that gave it unusually small timing windows. It was fixed for the arcade version of Happy Sky; the Normal difficulty was the fixed version, and Hyper contained the glitched one. But then, Konami decided to troll players further on RED CS with a new Another chart... which makes it even worse.
Even better, hidden codes on the home versions of DJ Troopers and Empress (spelling out "G-J-H" or "G-J-A" by highlighting songs starting with those letters, and pressing Select on each one) lets the player use those timing windows on any song.
Ascended Meme: Some Beatmania DJs themselves use the term "Nidera (弐寺)" instead of Two-D-X when talking about the IIDX series, and Ryu☆ described himself in the comments for Second Heaven as "That 'Somebody Scream!'guy" as a result of Misheard Lyrics.
Audio Adaptation: The ROOTS26S[uite] drama CDs centered around the DJ characters.
Beach Episode: Resort Anthem, ironically released shortly before the end of the summer season.
Bonus Boss: Beginning on Distorted, versions have featured new extra stage systems integrating with e-Amusement, where meeting certain conditions in-game unlocks additional boss songs in a themed area; usually only accessible on the Extra Stage, and always under themed aliases. Beating all the songs in the area will either lead to the True Final Boss as the One More Extra Stage ... or just lead to yet another tier of boss songs.
On Resort Anthem, this changed a bit. There were still bonus bosses, but instead of an Extra Stage system, they were now unlocked with "dellar points" earned in World Tour mode.
Lincle returns to the previous style with the Lincle Kingdom, the first three bosses involve playing sets with the EX-HARD modifier that are either of the same genre, from the same version, or by the same artist. This time, they were themed around the seven sins.
Tricoro has Legend Cross, which involves playing sets of songs from a single version to meet a goal that involves the number 573) to unlock an "Astran light" for that style. Bosses unlock once certain pairs of lights are obtained; each boss so far is a mash-up of other songs from their corresponding mixes (i.e. "SYNC-ANTHEM" is a mash-up of Tatsh songs from RED and Resort Anthem; you need to get both of their lights to unlock it). Clearing one of the bosses nets you a crystal. Get them all and you unlock Thor's Hammer. AAA'ing that song will unlock the OMES for Tricoro, Plan 8. However, playing Plan 8 removes half of your crystals and relocks Thor's Hammer. After an update in December 2012, players can now buy Devil and Angel Cards with points to unlock the songs for standard play; Angel Cards are more expensive, but allow the song to be unlocked even if it wasn't beaten before.
And now in Tricoro we have another bonus boss system, Omega Attack, a.k.a. Blockbusters: IIDX Edition. Playing the game earns CP, which can be used to buy weapons and upgrades to clear viruses off a map of hexagon tiles. While there are some other new songs and two CS exclusives among them too (i.e. "Tamayura" and "Reflection into the EDEN"), Sector A and Sector B both have one new boss-level song, "トリカゴノ鳳凰" and "Proof of the Existence". Unfortunately, the major flaw is that this system involves lots and lots of Level Grinding.
A milder example from the same game: While most Extra Stage songs are fast-pased songs with a sense of "hardcore"-ness, "ANTHEM LANDING", which serves as Resort Anthem's Extra Stage, is a more modestly-paced and somewhat mellow Latin-esque track.
Go all the way back to 10th and you'll find the boss song "One More Lovely", it sounds like it came straight out of a DDR game, and even has "HAPPY" as its genre. Yet, it will definitely make an inexperienced player frown, especially at the end (of course)
Since the implementation of the extra stage systems (which typically contain the harder bonus songs of a style), there will always end up being an Expert mode course which contains said songs. Class mode also provides the infamous Kaiden course, which usually consists of the 4 hardest songs available on that particular game.
tricoro's beatmania IIDX LIMIT BURST extra stage song, Sol Cosine Job 2, requires that you do this to unlock it—specifically, play three songs that have previously served as One More Extra Stage songs.
"Sense 2007" on Gold did this too, but with the much less frightening "WELCOME TO BLACK ROOM... IT'S PARTY TIME!!"
"Nageki no Ki" scrolled a whole bunch of words relating to grim subjects (DEATH GRIEVES DESTRUCTION MUTATION COLLAPSES SOLITUDE, etc.)
Boss Warning Siren: In beatmania IIDX, after unlocking an Extra Stage boss song, the music select BGM will be overriden by a short loop of the boss, or a new BGM altogether in beatmania IIDX 20 tricoro. In some cases, the background will change accordingly. This only applies to bosses that are made available on the standard music select screen, not bosses accessed through a special "boss select" screen (e.g. beatmania IIDX 13 DistorteD's Cardinal Gate or beatmania IIDX 16 EMPRESS's Empress Place).
Bullet Hell: It almost feels like that sometimes ... except you have to hit all the bullets!
Parodied in the Retraux song "Tranoid", whose video involves an arcade game consisting of Tran dodging notes directly from its Normal-mode chart.
Copy Protection: Unusually for an arcade game, tricoro has always-on DRM; it must be connected to an e-Amusement network or the game will refuse to start. (note the word "an")
While unusual by international standards, this type of arrangement (where an arcade game must be connected to its developer's subscription-based online platform, often accompanied by a revenue-sharing and leasing requirement) has been increasingly common in Japan.
Critical Annoyance: A lot of older songs played special animations in the video on missed notes. This happened more in 5-key and early IIDX though, but a few select songs on recent versions have had miss animations (most noticeably Anisakis). Most either contained Engrish ("WRONG PLAY BAD BOYZ KICK YOUR ASS") or otherwise made little sense (what does a salt shaker have to do with a cover of "Brazilian Rhyme"?)
Darker and Edgier: Soundtrack-wise, the entire series has gotten darker and edgier over the years. The first IIDX games were mainly house and R&B-oriented. 3rd to 9th Style brought more electronica, eurobeat, and trance. As Sequel Escalation demanded higher difficulty out of songs, hardcore music became a lot more prominent in recent versions. And now look at Tricoro, we got dubstep now.
This may be less due to Beatmania itself getting Darker and Edgier, and more due to changes in what's popular in the worldwide EDM scene.
RED and DJ Troopers were also pretty grim, design-wise.
Or better yet, SUPER STAR 満-MITSURU- : 満 means Mitsuru.
The Dev Team Thinks of Everything: If you use Legacy Note on a chart with no Backspin Scratches or Charge Notes, which Legady Note converts to standard notes, and clear the chart, the game will count your clear as a standard Clear rather than an Assist Clear.
Difficulty Spike: Konami makes sure the songs have more notes at the end before it can be in the game in order to enforce this.
Distracted by the Sexy: The original music video for "Last Message" in 7th Style has a 3-second cleavage shot, which has caused many players to accidentally slip up at that point. The video was unfortunately removed when it was revived on Gold CS, as Konami was trying to aim for the Japanese equivalent of an E rating (despite the fact that Last Message and its video was on 7th Style's home version already, and it seemed to have no effect on the rating)
Super Star -Mitsuru- begs to differ in ''She Is My Wife''. It's impossible to not be distracted watching kors k, Ryu☆, Yoshitaka, and Sota Fujimori taking part in it.
The song Attack! The Kneesocks Princess of Glass! shows off said princess, in what amounts to a bunch of see through versions of a maid outfit with cat ears. Makes sense, considering the song is about a princess trying to seduce a prince.
Fake Difficulty: You need your life meter to be at 80% or above at the end of a song to pass. Guess how the people who make the notecharts fake the difficulty...
Sirius has hold notes and a related note for the turntable where you have to continuously spin it one direction for the duration of the hold note and then snap it back the other way at the very end of the note. Fittingly, True Final Boss "Almagest" used them a lot.
In Dance Dance Revolution, "New Decade" relies on BPM gimmicks as one source of its difficulty. The song averts this trope in IIDX, where all of its charts are a constant 200 BPM.
A lot of the high speed boss songs (notably, the MAX series) start on a really low BPM. While this may not sound like much, higher level players who use the high speed mode need to pay attention. Higher level players use something called a "green number", which is how long the note is visible for. Lower BP Ms screw this up, but this is made worse with the floating high speed mode where it automatically adjusts the rate to match the green number... and it's not dynamic. Meaning a player who wasn't paying attention is now treated to say Fascination MAX at what would amount to 8x speed
Fanservice: Getting good grades on songs will also put different character art backgrounds on the result screen. Some of this may indeed qualify. No wonder the console versions have gallery modes.
To be specific, the names of the four gods are aliases of popular Bemani artists. They are, as follows...
Byakko = Tatsuya Shimizu, AKA Tatsh
Suzaku = Yoshitaka Nishimura, AKA DJ YOSHITAKA
Genbu = Jun Wakita, AKA wac AKA Shounen Radio
Seiryu = Ryutaro Nakahara, AKA Ryu*, who is well known outside of Bemani
Finally, there's a new 5th god known as Kinjishi, which means a combination of all 4 beasts. It's Takayuki Ishikawa, aka dj TAKA, one of the most prolific and famous Bemani composers of all time, and the music director for the Beatmania series itself, just as Naoki Maeda is the director for DDR.
Only Suzaku, Seiryu and Genbu have reappeared in further installments so far.
Game-Breaking Bug: 9th Style was the first Bemani game to use PC-based hardware, and it showed. Some songs had timing issues, Gambol was still broken, the One More Extra Stage "Quasar" sometimes crashed the machine, and playing "General Relativity" as the first song after a machine is booted triggers a hilarious bug which makes getting anything but POOR impossible. (Apparently, said song fell back on the timing windows of the previously played song. Since there wasn't a previously played song yet, it choked.)
Gimmick Level: Songs by DJ Mass MAD Izm* are infamous for having extraordinary numbers of scratches; on these songs, how good the turntable is on your controller or arcade machine can mean a whole world of difference. Some non-Izm songs, such as "Checking You Out" and "Plan 8", are also chock full of scratches.
Anisakis' miss screen reads "He set a foot wrong. However, it nothing but set a foot wrong. You set a foot wrong. It set a foot wrong so like him. The person commits an offense. However, do not set a foot wrong." Whatever that's supposed to mean....
Dellar points? And what the hell is a "Lincle" anyway? Same for Tricoro, which also has "Astran lights" as part of its Bonus Boss system.
And we can't forget about Michael in a boat, now can we? In reality, he was played by an American, Michael Stillwind (from Konami's Hawaii studio), and voiced by DJ Yoshitaka. Stillwind was notably responsible for his work on the Dance Dance Revolution Ultramix and Universe games, and for getting DM Ashura (who won a contest to get onto Universe 2, and then made some later contributions for Universe 3, which later crossed onto X2) a spot on Empress.
Harder Than Hard: Black Anothers. Dear God. The song MENDES (pictured in the lead) completely redefines Nintendo Hard (with 2,626 notes. The average boss has 1800-2000), and even the happy, up-beat eurobeat song Flowers isn't safe from this treatment, leading this troper to call it a "Yandere in Bemani song form."
Black Anothers are slightly Older Than They Think. The final two stages in Gold CS's Kaiden course, Vanessa and Kamaitachi, have special charts then exclusive to that course. When/If you get to these stages, you'll notice that where the difficulty should be shown, there is blank space. Later console installments give them proper Black Another designations.
Empress adds "Hazard"; One combo break and you're toast. On the plus side, you still get to play all the stages on your credit even if you do fail.
Lincle adds a new modifier, EX-HARD. This modifier increases the damage taken by the lifebar on misses to 18% at once. But just like the original HARD modifier, it removes the 80% passing requirement, but makes you fail the stage if it hits zero. If this isn't literally Harder than Hard, we don't know what is.
Tricoro brings the ability to set HI-SPEED below 1.0x (a.k.a. the LOW-SPEED modifier dropped after 6th CS). 灼熱Beach-Side Bunny on half-speed looks a lot worse.
Idiosyncratic Difficulty Levels: Formally Light 7, 7 Keys, and Another. Happy Sky adjusted the ranking scale and re-named the first two to Normal and Hyper.
When it was first introduced, Another was actually another arrangement for the song, typically harder and more complex. Now? Nine times out of ten, it's just a harder chart.
High Definition: Although the arcade IIDX series uses widescreen monitors, only in tricoro did the series actually support proper 720p HD. In fact, games up to tricoro ran in 640x480—that means technically, the graphical assets you see on screen are actually stretched!
A mode on the PS2 versions allows the gameplay screen (which typically use a special 4:3 optimized screen layout) to use the arcade versions' widescreen layout, stretched into a 4:3 frame. Much like the arcade version, you stretch it on a widescreen display to make it work as intended
Last Note Nightmare: Due to the 80% lifebar requirement for passing, a song with a ridiculous ending is practically a series trope on its own.
Although, it can be easier with HARD on.note The HARD modifier swaps out the 80% life bar for a traditional lifebar where you only fail if you hit 0%. Thus, HARD actually makes songs with hard endings easier to clear as long as you can stay alive.
Level Grinding: One of Lincle's unlock methods. tricoro's Omega Attack event, a post-game board game, takes this to WTF levels; completing the first sector takes at least forty playthroughs. The less said about the second sector, the better.
Lost Forever: tricoro's color events have several songs crossovered from console IIDX games, all of which were originally gone permanently if you failed to unlock them during their respective events. This was changed in an update (on August 14, 2013, over 8 months after the first event ended) which allowed players to buy the unlocks using Dellar points, at 5K for Normal, 10K for Hyper, and 15K for Another. It requires tons of Level Grinding, but they can once again be unlocked if you missed them the first time.
Marathon Level: Scripted Connection⇒ & Shade, both lasting about 6 minutes long. Both by the same artist to boot. You see, the part of the song you actually play is dependent on the difficulty, and the soundtracks have the full version as all three versions strung together. However, on the console version of Happy Sky (and beginning on Gold AC), all three versions of Scripted Connection have full sets of charts (the N-mix, H-mix, and A-mix respectively). The "long mix" of Scripted Connection is also a hidden track on Happy Sky CS, where it clocks in as the longest single song in the entire series.
Resort Anthem's extra stage, ANTHEM LANDING, also counts as this despite having no long version to play.
Tricoro has 仮想空間の旅人たち (Kasoukuukan no tabibitotachi) which does the same thing, except between the single and double versions.
If you are using a Groove Gauge in whch a 0% is instant failure, any damage you take while your Groove Gauge is 30% or less will be halved.
In tricoro, the requirements to unlock a LIMIT BURST song, other than playing a 3-stage set of songs from that song's game and qualifying for extra stagenote on your last stage, all-Great combo a level 5 chart or lower, Full Combo a 6, finish a 7 with 100% gauge, or simply clear an 8 or higher, are initially extremely harsh, but relax every week:
Phase 1: You need your first three stages' difficulties to add up to 33note To put it in perspective, this means the average difficulty of your songs must be 11 or higher AND you need a Full Combo! And even then, only the Another chart will be available.
Phase 2: You now only need to clear the three stages with an EX-Hard gauge. In addition, the Hyper chart becomes available, and requires a total difficulty of 27note average difficulty 9 or higher and a Hard gauge.
Phase 3: Another only requires a Hard clear, Hyper only requires a standard clear. Normal finally becomes available; you need a total difficulty of at least 18note average difficulty 6 or higher, and it will unlock as long as you clear your songs at all (even Assist Clear).
Phase 4: Just clear all three stages (again, Assist Clear is OK).
If you fail a chart that is less than level 6 for your first stage, you'll still be allowed to advance to the next.
If you are playing on a machine that is connected to the official e-Amusement network, you can use PASELI (proprietary e-Amusement currency that you purchase with real money) to purchase a DJ Vip Pass, which is a pay-to-use Mercy Mode: you'll be guaranteed three stages even if you fail your first two.
Minigame Credits: DistorteD's credits roll lets the player spin around the camera angle on the monotonous 3D backdrop soaring through the background with the turntable, it's not a "game" per say but still.
SIRIUS's credits roll has a spinning disc in the background that can be manipulated with the turntables.
Subverted by Empress, while the credits are not a minigame, the ending theme itself became a playable track ("THANK YOU FOR PLAYING") as part of the final set of timed unlocks, with the credits roll as its background video. Ironically, the song has been revived past Empress, and it still has Empress's credit roll attached to it. The ending for Resort Anthem, "Everlasting Resort", also does the same thing. Will someone ever notice and switch it out with a generic video? At the rate we're going, no.
The subversion is averted for "Vermillion" (Sirius ending theme, debuting on Resort Anthem) and "The Last Striker" (DJ Troopers ending theme, debuting on the PlayStation 2 version), which got their own dedicated videos when they became playable tracks. In the latter case, its a Clip Show of generic videos.
Mission Pack SequelIIDX has about 19 installments to its name, each with different art/song themes. Not exactly Capcom Sequel Stagnation though, since every mix has new songs, new features, and often remove or bring back older songs,
Capacity Gate's unlockable menu music on Resort Anthem is a remix of the Dance Dance Revolution Extreme menu music.
Nintendo Hard: IIDX is regarded by many Rhythm Game conoisseurs as one of the most hardcore rhythm games in existence, if not the most hardcore.
The groove meter 80% passing grade for all songs greatly contributes to this.
Unlike the other Bemani games, beatmania's timing is actually based on the amount of frames the button was pressed before or after the note passes the marker. By default, the Just Great timing happens on the frame or the one before, meaning a player has about a 16ms window of time to hit a note "perfectly".
No Fair Cheating: Scores achieved with the "Auto-Scratch" modifier don't get saved. In IIDX, this applies to the "5 keys" modifier as well. With the introduction of continuous notes in IIDX 17, the Legacy Note modifier which removes these has the same effect. Currently, scores with such "Assist" mods will save, but will be marked with "Assist Clear" status. This is because while Assist mods will make songs easier to clear, they provide no benefit to your score as they deduct playable notes.
This backfires on people who use the 5key modifier on classic beatmania songs. Using the modifier on them will load up the old 5key chart from beatmaina, but will still count it as an Assist Clear.
Promoted Fanboy: One of the top ranking players, DJ DOLCE., has appeared on a video special for IIDX 16 Empress, won two out of the four official tournaments, and has met some of the most known Bemani artists (e.g. DJ Taka) along the way.
DM Ashura got his start by remixing music from Dance Dance Revolution among other bemani games. As he's won several contests to have his songs included in the DDR, he was asked to make a song in EMPRESS.
Public Domain Soundtrack: Not rampant, but many classics in the series ("V" and "Kakumei" especially) are indeed remixes of other classical pieces ("The Four Seasons: Winter" and the "Revolutionary Etude", respectively)
Rage Quit: Seeing "78%" (2% lower than the required gauge to pass the song) tends to cause this.
And then there's this one guy. Skip (or watch all the way) to around 2:06.
Rank Inflation: Grades go from F to AAA. Similarly, in Class mode, you have the 7th through 1st kyu grades, then 1st through 10th dan, and finally, kaiden.
Recurring Boss: While dan course songs tend to scramble around with each new version, "THE SAFARI" in particular is notorious for consistently being the last stage of single-player 7th Dan, a position it's had since the introduction of the kyu/dan system on 7th Style in 2002. "gigadelic" is also notorious for this in 8th Dan, where it's been the final stage in every version since the song was introduced in IIDX 11: RED, with the sole exception of IIDX 15: DJ Troopers.
Recurring Riff: Every Suzaku song has a distorted guitar screech in it, appropriately dubbed by many fans as the Suzaku Scream.
Recycled Soundtrack: Songs will often be continually "revived" (remaining alongside new songs on a newer version of the game, or appearing alongside older songs on console versions) quite a few versions, especially if they're fan favorites.
"V" is notorious for this. It debuted on 5th Style, and got revived on almost every console version after that until IIDX 1). Fans suspected Konami of "ruining the joke" that "you can't spell 'revival' without 'V'".
Then, Empress brought us "V2" ... which was nothing more than a cut of an extended version of V from dj TAKA's album "milestone".
Required Spinoff Crossover: Throughout practically every Bemani game actually, songs will often cross over from Beatmania to other games, or vice versa. Special mention goes to Kakumei, a collaboration between dj TAKA and Naoki (who were both the producers for their respective franchises at the time), which appeared as the One More Extra Stage on both IIDX 7th Style and DDRMAX2, both of which were the 7th main release in their respective series. At the same time, a version of "MAX 300" (which was the Extra Stage song on DDRMAX, a first for the series) was also the main Extra Stage on 7th Style, it too being the first Extra Stage in the series.
A few other DDR boss songs have appeared since, including Sakura (Extreme extra stage, 8th Style extra stage), Paranoia Survivor Max (Extreme extra stage, 9th Style unlock), Fascination Maxx (SuperNOVA extra stage, as Gold OMES), Pluto (SuperNOVA 2 extra stage, unlock on DJ Troopers CS), and Saber Wing (DDR X extra stage, beat unlock on Resort Anthem). While not a boss song, Sakura Storm (DDR Universe 3 and X2) also came up as an unlock on Resort Anthem.
The "Nadeshiko Rock" song from Pop'n practically crossed over to every active Bemani franchise, IIDX included, around Empress.
And then there's DJ Yoshitaka's "FLOWER", which does the same, though it had to be retooled into a rock arrange for Guitar Freaks & Drummania.
Then came the LincleLink and events for Resort Anthem and Lincle, whose point was to allow players to unlock songs from the latest Jubeat versions on IIDX and vice-versa by playing certain combinations of songs on both. Lincle also brought the "Append Travel" event, which brought more promotional Jubeat crossovers to other Bemani titles as well.
Tricoro's other Limit Burst songsnote There is no "default" Extra/One More Extra Stage-only song like on previous versions, but there are still conditional unlocks only available on the extra stage labelled on the results screen as "LIMIT BURST" songs. have all been boss songs from other Bemani franchises. So far, these have included a new mix of "New Decade" from Dance Dance Revolution X2, "neu" (That One Boss from Pop'n Music Adventure), "Hollywood Galaxy" from Reflec Beat, "DAY DREAM" from DrumMania and GuitarFreaks, and "Timepiece Phase II', also from GF&DM.
Retraux: The Parallel Rotation extra stage system in SIRIUS, which echoes 5 of the previous 6 styles.
Rule of Fun: It's not really DJ simulation anymore. But does that really matter?
Schedule Slip: Up until 6th Style, PS2 ports of IIDX games were generally good with being released within one year of their arcade counterpart. However, 6th Style took about a year for a home release, and 7th Style infamously took two years. Fortunately, the home IIDX titles started being released with regularity again afterwards... until Empress.
Then there's also a mode called WINDOW HOLD, which keeps the in-song HI-SPEED and SUDDEN+ controls active after hitting Start (instead of requiring you to hold it down). The joke of this is that because the keys and turntable respectively are used to configure those settings, you're supposed to play the song with them constantly changing on every note!See?
Sequel Escalation: The difficulty scale originally went from 1 to 7. Then came the 7+, which were later relabeled as 8. Then there were 8+s. Then Version 12 bumped it up to be out of 12.
But, The Computer Is A Lying Bastard. Before Happy Sky introduced 9-12, the 7Keys/Hyper difficulty rating would be exactly the same as the Another difficulty rating. This caused hard songs to be mislabeled. One of the most egregious examples is "Mr. T (Take me higher)", rated a 10 on Another after Happy Sky, to be labeled as a 4. Even worse than that is "5.1.1.", which up to Happy Sky was rated a 1 on Normal and Hyper, but has a prettybrutal Another chart.
Series Mascot: Tran, the Humanoid Alien, he appears in several background videos. But, this hasn't stopped the individual versions from having their own mascots.
There's also the various (mostly female) DJs that go on the promotional art.
Spell My Name with an S: A number of songs have multiple ways to read their names; "Shonen A"/"Kid A" (not that one), and "Gattai Sayo! Strong Jaeger!"/"The Strong Jaeger," just to name a few. This is primaraly a result of the cabinet's LED marquee: since it can only display English characters, songs with foreign titles will either be romanized, translated, or show something completely different on the marquee.
Standard Snippet/Sampling: A sampling-related conspiracy theory occurred in two particular styles: a stock sample of someone yelling "SOMEBODY SCREAM!" appeared in two different songs on Gold (Second Heaven and FIRE FIRE, but more infamously in the former), followed by a sample of someone saying "1-2-3-4-5-6 do it!" appearing on three different songs on DJ Troopers ("Be OK", "Icarus", and the aptly titled "Do it!! Do it!!", which consisted almost entirely of that sample.) Even more ironic was the fact that the last of those two were both Military Splash songs.
"Schlagwerk" takes a couple lines from Bad Boys: "Oh, this is bad." and "This is fucked up!"
Stat Meters: RED added a new stat display (typically shown on the other player's unused play field), which shows a series of bars comparing the player's current score to that of an optional rival or the high score.
Stellar Name: Jun Wakita's trademark. "Regulus", "Spica" and "Scorpion Fire" are all named after stars (SF is an allusion to Alpha Scorpii/Antares), "moon_child" and "Ganymede" refer to moons, and "Waltz of the Big Dogs" refers to a constellation.
Tag Line: Most games in the series have one, ranging from the simple ("It's party time!" from GOLD) to the nonsensical ("Next Link Various Tunes Change the World [ TRI ] For The Future !!!" from tricoro).
Take That: When Ryutaro Nakahara stopped using an asterisk and started to use a star for his Ryu☆ alias, his brother kept asking his "What's with that?" The song Be Quiet is his answer.
The Artifact: Remember back in the day? When this game actually did primarily have hip-hop, and as such an actual justification for having scratching in its controls? Yet, it remains, even though most of the songs are now either hardcore electronica or pop. The IIDX series did start with mostly J-pop and R&B, but then began to diversify, to the point where on most songs, the turntable is just another trigger for sounds that aren't scratching.
That hasn't stopped songs with legitimate scratching from showing up in the modern era though. Just beware if you encounter a song by recurring regular "Dj MASS Mad Izm*"
Theme Naming: Since the 11th main installment of the IIDX series, every installment has had some sort of color theme to it, with a subtitle relating to the colors, such as "RED" (Revolutionary Energetic Diversification, primarily all dark red/black), "Happy Sky," (skies and clouds) "Gold," (all colored in black and gold with a VIP club-like motif), "DJ Troopers" (military and camouflage), "Empress" (pink and black with jewel motifs), "Sirius" (metallic silver and blue space-age), "Resort Anthem" (summer, beaches), "Lincle" (blue, orange, and white with some atom trails), "Tricoro" (mostly white and black with lots of 3D abstract stuff, and red/blue/yellow elements), and now "Spada" (Italian for "sword"; fittingly, its dark and medieval looking. Even the grade graphics, which had barely changed since 9th Style, got changed to use a more medieval font)
Also, the Extra Stage songs often have some kind of theme to them. See The Four Gods above. IIDX 16: Empress also has a set of regular One More Extra Stage songs with a sweets theme and an alternative Extra Stage called EMPRESS PLACE that centered around former "empresses" like Cleopatra and Marie Antionette.
Similarly, in 15th Style: DJ TROOPERS, there is a new version of Cardinal Gate called Military Splash that has 4 Bemani artists hiding their identities behind battle formation aliases.
Lion = dj TAKA
Scorpion = Toshiyuki Kakuta, aka L.E.D.
Kraken = Ryu*
Eagle = Kosuke Saito, aka kors k, who is also a known artist outside of Bemani
Humanoid = DJ Yoshitaka
In Sirius, the extra stage system was a series of Nostalgia Levels based off versions 11 through 15. Each tier had two previously console exclusive tracks, a new remix of a song from that version, and a new song performed under an alias used by a boss song on that version. When played, the songs even used the matching interface skins from their respective versions.
On Lincle, the extra stage system was themed around the Seven Sins.