The gameplay takes place in a side-scrolling perspective, with your character running along and hitting enemies in time to the music; attacking enemies is done by pressing buttons corresponding to the ground or the air.
Compare Taiko no Tatsujin, another horizontal-scrolling rhythm game.
Trope Dash! Ready...GO!
- The Artifact: Some of the loading screen messages suggest that you tap the screen with more fingers to hit faster chains, or rotate your device for a different experience. These messages remain in the Steam version, where they won't make sense if playing on PC. However, its release on the Steam Deck, which has a touch screen, gave some of its relevance back.
- Becoming the Costume: Many characters take on different voiced lines when you put on their alternate outfits. For example, putting Marija in the Maid outfit turns her into a Reluctant Fanservice Girl who asks her "master" to be a little more "gentlemanly" to her, while putting her in the Girl In Black outfit cranks her dominatrix elements up to eleven.
- Button Mashing: The "punching bag" enemies give you a set amount of time to mash buttons as many times as possible for bonus points. Some bosses also have finishers that work the same way.
- Colour-Coded for Your Convenience: Anything that goes on the bottom lane is pink, anything on the top lane is blue. Or rather, it is the lane whose button you need to press, as exemplified by the barriers that can only be dodged by moving to the other lane.
- Crossover:
- There's one with Groove Coaster, adding not only songs from it but also the character Yume.
- On February 5th 2021, the game added a crossover pack for Cytus II, adding a total of 12 songs technically 13 if you count the glitch version of Chaos hidden on the title screen that accompanies the pack along with the game's second collab character, Neko#ΦωΦ
- The September 3, 2021 update featured a collaboration with game developer 7th Beat Games, featuring songs from A Dance of Fire and Ice and Rhythm Doctor, as well as including a new elfin, Doctor Paige.
- September 30 2021 has one with Touhou Project, which features its protagonist, Reimu Hakurei, as a playable character, and up to ten arrangements of songs from the franchise. On the same day in 2022, the other protagonist, Marisa Kirisame, was added alongside seven more Touhou song arrangements.
- In November 2021, the game would get their second arcade collaboration with WACCA.
- In December 2021, the game got one with Arcaea, notably marking the first time Arcaea collaborated with a non-arcade game in two years.
- In January 2022, they added a collaboration with NEEDY STREAMER OVERLOAD, adding its theme song and an illustration based on the game.
- Within the same month, they also collaborated with DJMAX Respect V, adding 15 new songs from the game as well as including El_Clear as a playable character.
- In January 2023, they released a collaboration with Arknights, including a number of their songs under the Monster Siren Records Label, adding Amiya as a playable character, and even adding UI elements from Arknights into the game (for example, the ranking letters in the Results screen take on the stylized appearance from the Results screen of the Contingency Contract content, in particular the interlocked double and triple S ranks).
- Damn You, Muscle Memory!: Sailor Buro has the ability to allow you to hit chains of notes in quick succession by hitting the first note of the chain (marked with a double-circle) and just holding the input down to hit the rest of the chain (marked with a single circle). Utilizing this to its fullest extent requires unlearning the "must hit the input for every note" mentality that every other character demands and instead learn where the chains start and end, treating those as hold notes. This is a far harder task than you would think. Furthermore, any ghost notes that occur in a chain don't count as part of the chain and must still be manually hit, though you can hit a second button for the appropriate input to hit them without worrying about dropping your chain.
- Deliberately Monochrome: The song "Bad Apple!!" of the Touhou Project update features all objects and characters solid black against a white background, harkening to the style of the (unofficial) music video for the original song.
- Developer's Foresight: Sleepwalker Girl Rin is completely invulnerable in normal gameplay, as she automatically plays a chart for you and won't miss or get hit by objects. If the player manually disables this and lets her health run out, she has her own game over screen and accompanying voicelines where she starts waking up and wondering where she is.
- Difficult, but Awesome:
- On charts where the LD Marija + Lilith combination is possible, they are easily the highest-scoring combination in the game due to their score multipliers.
- Manual Fever allows the player to score higher than with automatic Fever, but only if they know the optimum spots for activating Fever and if they can juggle pressing the command for Fever with whatever the charts throw at them.
- Do Well, But Not Perfect: Some chart-specific missions require you to get hurt a set number of times (dodging an enemy doesn't count, you have to run into it; running into the enemy while under any form of invincibility doesn't work either, you have to take damage) and still clear the chart.
- Downloadable Content: The Steam and smartphone versions have most of the tracks available in DLC packs. The Switch version does away with this and has all the songs available without having to make additional purchases, at the cost of a more expensive base game and delayed updates.
- Future Funk: The Muse Radio folder is dedicated entirely to songs of this genre.
- Game-Breaking Bug:
- The Switch version had an issue with hold notes wherein if one hold note ended at the same time as the start of a new hold note, it could happen that you would fail to latch on to the second note, missing it entirely, even if your character was clearly shown reacting to your button input. This seems to have been patched out.
- The update that added Sailor Buro also broke double-input notes on Steam, both for everyone with regards to holds that start simultaneously AND separately for Sailor Buro players with regards to chain notes. In the first case, all you get is a combo drop (and, if it was a blue hold, your character ends up on the ground). In Sailor Buro's case, you will get hit by the notes that would normally be auto-hit. Workarounds exist for both: disabling VSYNC and removing the frame limiter reduces the likelihood of the bug happening significantly, while intentionally offsetting one of the two inputs so that they don't occur on the same frame almost always prevents the bug from happening.
- Glass Cannon: Little Devil Marija gains a whopping 25% score bonus when hitting enemies, but she loses 10 HP per second. You can equip Lilith in combination to get 2 HP back per Perfect but she is still by far the riskiest character in the game and literally renders easier charts Unwinnable by Design, since there simply aren't enough enemies to absorb health from.
- Harder Than Hard:
- Master difficulty, above Hard; it is available on most (but not all) tracks. Unlocking it for a particular track requires getting an S rank (90% accuracy or higher) on the track's Hard chart.
- "MopeMope" has a level 9 Master chart, followed by a hidden level 11 chart, i.e. Harder Than Harder Than Hard.
- Taken to a new extent with XODUS, which has a Master 11 chart... and a Hidden Master 12 chart, the first chart to receive that difficulty rating in the game.
- Hot Witch: Marija in her Magical Girl outfit boasts a Boobs-and-Butt Pose that has her flaunting her panties with a grin on her face and gains a number of lines involving seduction and magic.
- Intentionally Awkward Title: Not the game title itself, but the name of the development team, PeroPeroGames. Pero pero is a Japanese onomatopoeia for (perverse) licking.
- Similarly, HasuHasu, a subsidiary of PeroPeroGames, comes from the Japanese onomatopoeia for (sexually) excessive breathing.
- Invincibility Power-Up:
- Pilot Buro becomes invincible whenever she's in Fever mode.
- Neko#ΦωΦ enters an invincible state once her HP is depleted to zero, however clearing the song in this state does not record your score.
- Jiggle Physics: The girls are very animated in their movements, and yes, they bounce quite a lot.
- Last Chance Hit Point: Zombie Girl Buro can activate "Dying Mode" if she takes damage that is supposed to knock her out; she merely drops to 1 HP and becomes invincible for 15 seconds. Once the invincibility ends, she cannot trigger it again without picking up a heart.
- Mechanically Unusual Fighter: Reimu and Marisa have a passive ability to float, and will stay in the designated up or down areas, whereas most other characters typically jump and attack high to stay in the air and will fall after attacking.
- Mercy Invincibility: You're briefly invincible when you take damage from an enemy or an obstacle. The Thanatos Elfin extends the duration of the invincibility.
- No Fair Cheating:
- Playing as Sleepwalker Girl Rin will cause the chart to be played automatically. Unsurprisingly, this does not change your records, give you EXP, or fulfill any achievements or challenges.
- Neko#ΦωΦ becomes invincible once she loses all of her health, but clearing the chart after becoming invincible will also not change your records or give any reward.
- No-Sell: Yume from the Groove Coaster collaboration is immune to damage from gears, although she will still get Misses on them if she gets hit (as opposed to Passes).
- Non-Standard Character Design:
- Sailor Suit Buro looks noticeably different than any other playable character, including the other versions of Buro. The accompanying Muse Radio backdrop has boss design and poster artwork in a similar art style.
- Part-Time Warrior Rin is drawn in a simple, scribbly style unlike anything else in the game, complete with only a few frames of animation. She was released as part of an April Fool's update claiming PeroPeroGames were running out of money, explaining her simplistic look.
- Power Nullifier: Silencer, an Elfin exclusive to the Just as Planned DLC pack, has the ability to disable the abilities of any character she's paired with, and set that character's default HP to 250. This makes them one of two Elfins that prevents Little Devil Marija from being an Unwinnable by Design character.
- Rank Inflation: After A rank, there are three S ranks: A red S-rank for accuracy above 90%, a silver S-rank for 95% or more, and a gold S-rank for 100%.
- Secret Level:
- Befitting of its surprisingly creepy nature, the song "MopeMope" has a Master chart rated 9... and another, hidden Master chart rated 11, unlocked by tapping on the Master icon until you get a popup that reads "The Ultimate Children's Day Gift". In other words, it's Harder Than Harder Than Hard. The part that warrants the rating is naturally, the part where the song's creepy moments stop being momentary and last for 30 consecutive seconds.
- The Cytus Collaboration brought over a few songs from Cytus II, with a couple getting a Hidden Master chart. It also brought over NEKO#ΦωΦ as a usable character, and an animated Title Screen Background... which conceals the Glitch version of Chaos, accessed by answering the phone. This last bit isn't even hinted at in the update notes on the update and is likely something you'd only think to try if you've also played Cytus II.
- From the same update, XODUS. Hidden Master charts haven't been a new thing, but XODUS already had a Master-11 chart, and every Hidden Master chart has been rated above the corresponding normal Master chart. Well, XODUS still received a Hidden Master chart, which was given a rating of 12, the first chart to ever be rated that high.
- Set Bonus: Playing as Little Devil Marija and equipping Lilith as your Elfin grants you a 2 HP recovery each time you get a Perfect. This does not make Marija an Infinity +1 Sword, as she needs that health recovery to survive.
- Stylistic Suck: Part-Time Warrior Rin, a version of Rin drawn in a simple, scribbly style, complete with only a few frames of animation and no voice acting. She was released as part of an April Fool's update where PeroPeroGames claimed they were running out of money and thus couldn't afford anything better.
- Super Mode: Fever mode, which is earned by hitting notes to fill the Fever gauge; once the gauge is full, enemies are worth additional points until the gauge runs out. Certain characters and Elfins gain additional effects in Fever mode, such as increasing the Fever point bonus or granting invincibility until Fever ends. A later update to the game allows the player to manually deploy Fever instead.
- Superpowered Evil Side: or Evil Twin case. Marija as The Girl in Black (who's one of the hardest costumes to unlock and who's specialty is the ability to plow through mooks easily, represented by her having an easier time scoring perfects) is a boss you fight in some tracks, complete with the same car and henchman from her character select screen. Another one of the bosses appears to be a grey-haired Buro piloting a UFO, although maybe this is just an evil look-alike as playable Buro doesn't have a costume confirming it's her, unlike Marija's case.
- Unwinnable by Design: Little Devil Marija makes easier, less dense charts literally impossible to complete simply because there aren't enough hearts to offset her 10 HP per second depletion; at 200 HP, she will fail in 20 seconds and no track in the game is anywhere near that short. Even if she also equips Lilith to restore 2 HP per Perfect and hits every enemy perfectly, she will still lose if the chart isn't dense enough.
- Though, if one manages to get the Elfin Silencer, there's the option to disable Little Devil's skill altogether.
