- Anti-Climax Boss: Chapter K from Cytus is back, split into the Knight Iris and Knight Rosabell books. "The Fallen Bloom", representing the chapter's climatic duel between Iris and Rosabell, is rated only a 7 on Hard. To compare, the first song in the duology, the happy and peppy song "The Way We Were", is rated a 9 on the same difficulty.
- Epileptic Trees: Following the Disturbing Number entry from the main page, there were many different theories of what Deemo is about, one of them is that Deemo is someone important to the girl and the songs also give hints of Foreshadowing of what truly happened to the girl. "Run Go Run" was a blatant one which foreshadows that the girl was involved in a car accident.
- Then there are theories that the masked lady is someone in real life who wanted Deemo to give up on the girl.
- Most of the thought up theories had been confirmed as of the 2.00 Update.
- Polished Port: Similar to Voez, The Nintendo Switch version has the songs unlocking through natural progression in the story, and fixes the below criticism by simply making it to where you don't have to buy any song packs. It's fully inclusive.
- Scrappy Mechanic: On top of paying 2 USD for the game, you have to buy song packs unless you like having your tree grow in microscopic increments per song played, since you only gain significant tree growth for playing a song for the first time or getting either a full combo (not missing a note) or a 100% combo (getting a full combo and all charming notes). Sometimes the game goes on sale...which is pointless because 1. it's only a $1 discount, and 2. the DLC song packs never go on sale. Fixed in the 3.0 update, in which light orbs occasionally appear to give you substantial tree growth or steps progress.
- That One Level:
- The debate of the most hardest songs changes in each version. As of now, Anima is the placeholder of the hardest song among all of the free songs for Deemo.
- For the Vanros Kloud pack, Pure White takes the cake.
- The M2U pack has Lune.
- In the Shattered Memories pack, Run Lads Run is this due to the high tempo and fast pacing. It's even called "The second coming of Anima".
- Aragami rivals Anima in sheer difficulty.
- The Forgotten Hourglass update adds Extra difficulty charts to existing songs. A few of the songs happen to include Anima and Aragami. Have fun!
- Say hello to Marigold, the final unlockable song in the Forgotten Hourglass update, which makes Myosotis and Anima look like Easy songs in comparison. It is rated 12 on the hard difficulty. Have fun.
- The Woobie: The Little Girl/Alice and the Masked Lady/Celia. Oh boy...
- Alice starts off the game perfectly fine. She's a bit amnesiac and afraid at first, but she was fine... Until The Reveal strikes. It turns out that her brother died protecting her from a truck, and she was knocked into a coma due to this. When she realized that Hans was dead, she broke into tears, and when she woke up, she still broke down. This poor girl...
- Celia is the name of the Masked Lady. She is the side of Alice who wanted to stay with Hans when he died, by staying in her coma, effectively killing herself. What a Broken Bird...
YMMV / Deemo