YMMV / Touhou Kaikidan ~ Mystic Square

• Alternative Character Interpretation: Does Mai really see Yuki as "dead weight", or was she only pretending in order to avoid showing weakness in front of the player character?
• Ensemble Dark Horse: Mai and Yuki have a fair share of fans due to their Sequential Boss dynamic along with being the series's first full-fledged Dual Boss (albeit the second game had a dual midboss), as well as their seemingly one-sided friendship that adds more immediate depth to their characters compared to other bosses.
• Fan Nickname:
  • The unnamed Stage 1 midboss has been referred to as "Wheel Demon".
  • The mirror that appears as Stage 2 midboss has been referred to as "Spirit Mirror".
  • Louise's appearance as the Stage 4 midboss is sometimes called "Blouise", as a pun on her Palette Swap.
  • The unique lasers found exclusively in this game's fourth, sixth and Extra boss fights, due to their (usually) yellow color, large sizes and tendency to curve are usually known as "Cheeto lasers" or just "Cheetos".
  • The unnamed Stage 5 midboss has been called Ayana (妖奈), meaning "bewitching".
  • The section of Stage 5 right after the midboss is one of several stage segments throughout the series to be nicknamed "Spam". In this case, it's due to the sheer volume of danmaku of different colors and shapes, which makes it tricky to maneuver and easy to either miss the aimed shots, fail to dodge them, or dodge into other bullets.
  • Shinki's penultimate phase is typically referred to as "Devil's Recitation" due to its similarity with the Spell Card of the same name in Undefined Fantastic Object.
  • The card that acts as midboss in the Extra Stage has been dubbed "Trump King" due to the crown they wear, despite actually being a Jack.
• Fanon: Fan depictions of Shinki as Alice's mom are common. This has also led to many works with the idea of Shinki going to Gensokyo every now and then to pay Alice a visit.
• Hilarious in Hindsight: This game has a Dual Boss, where one of the two characters is named Mai (マイ); Touhou-inspired shmup series Seihou would do the same with twins Mai (まい) and Mei, and within Touhou itself, Hidden Star in Four Seasons would do it again with the backup dancers, one of whom is named Mai (舞) Teireida.
• Low-Tier Letdown: Yuuka isn't very well-liked as a shot type in this game. Her spread shot has so little damage it may fail to kill enemies quickly enough to make her effective at cleaning up stages, and isn't much help against bosses either. She's also tied with Reimu (who has better damage as well as homing shots) for the slowest shot type in the game, making it harder to collect the point items required for extra lives and dodge certain kinds of attacks. Her only positive is having the longest bomb in the game (albeit she only beats the aforementioned Reimu by a slight margin), and even that isn't very useful in the Extra Stage due to Contractual Boss Immunity.
• Signature Scene: Shinki's penultimate pattern. Not only is it visually stunning, it's also well-known for being the likely inspiration for Byakuren's spell "Devil's Recitation" in Undefined Fantastic Object.
• That One Attack: Shares a page with the rest of the series.
• That One Boss: Also shares a page with the rest of the series.
• That One Level: Stage 4 can be this to some players, because several enemies fire bullets that are a similar tone of blue to that of the background, and thus the bullets can be harder to see. This one stage is so notorious for this visibility concern, that it single-handedly sparked a misconception that all of PC-98 is like this.