All songs in DEEMO have three difficulties by default: Easy, Normal, Hard.
There is also a fourth difficulty, Extra, which exists only for a few select songs and are only unlocked in Forgotten Hourglass playthroughs.
The difficulty of a song can be identified by its difficulty icon: a coloured circle with a music note inside, with its note value corresponding to the difficulty.
Levels[]
In addition to the difficulties, every song in DEEMO is ranked based on its toughness to play. Each difficulty has its own toughness which is represented by its Level. Levels can range from LV1 to LV12; the higher the level, the harder the song. The Extra difficulty of certain songs have unique levels which are not numbered and it is impossible to determine the difficulty from the level alone.
For the same song, a higher difficulty has a level greater than or equal to a lower difficulty. Different difficulties of a song with the same level have different note charts (e.g. Jumpy Star Easy LV3 and Normal LV3 are different), but this indicates that the harder difficulty is only slightly harder.
Easy[]
The Easy difficulty icon is a green circle with a Crotchet.
This difficulty simplifies the notes and rhythms, making it as simple as possible. Typically, songs will not have an Easy level greater than LV4. There are several LV5 songs, but the extreme end of the Easy difficulty is LV7.
In Easy difficulty, multiple fingers are typically not required to be used simultaneously (unless two notes fall down at the same time), and in most cases the use of two hands is unnecessary. Sliding notes are also usually short and simple (with the exception of Saika, with the sliding notes at the bridge being comparatively challenging).
Newcomers are encouraged to try out this difficulty first before challenging others, though more experienced players (including those from other rhythm games) may find it boring.
Normal[]
The Normal difficulty icon is a silver circle with a Quaver.
Song charts falling under the Normal category have an increased difficulty, with most songs being LV7 or below. There is the exception of a few songs with an uncommon Normal difficulty level of LV9.
This difficulty generally requires the use of two hands or possess long hand spans. Also, single taps appear more often. On certain songs such as Wings of piano, Tap and Slide notes will appear simultaneously.
All songs in the Etude collection don't have a Normal difficulty, only having only Easy and Hard difficulties.
Normal difficulty is generally for more experienced players, and serves to train players for the Hard difficulty.
Hard[]
The Hard difficulty icon is a gold circle with a Semiquaver.
Hard used to be the highest difficulty within the game before the 3.0 update. The levels vary greatly, with the easiest end of the spectrum being LV4 and the hardest end being LV11. There is one song with a unique Hard difficulty level of LV12, Marigold. Achieving even a Full Combo in this difficulty is very challenging.
Hard levels require great amounts of skill, with some songs requiring rapid change of hands and others having two sliding notes appearing together.
This is more challenging and is more suitable for veteran players. Train yourself enough before challenging this!
Extra[]
Once the Extra difficulty is unlocked for a song, an icon with the letters "EX" will display next to its difficulty icon, regardless of the difficulty selected.
The Extra difficulty icon is a cyan-pink circle with a Dotted Quaver.
The Extra difficulty was introduced with the 3.0 update for a select few songs. Extra difficulty levels might not necessarily be numbered but may have letters instead (e.g. LV xi).
This difficulty may require the use of 3 or 4 fingers to play; for example, Magnolia LV M and Altale LV S feature triple tap and triple slide notes, respectively. Users with small device screens may find difficult to manage. It also requires speed in addition to skill as notes are spaced very densely.
Extra difficulty challenges even the most seasoned of players. You should become accustomed to LV11 songs before attempting this.