This is a lesser-known character piece from the 20th century. It explores romantic textures within a modern harmonic framework.
The primary challenge is maintaining a consistent lyrical line against varied rhythmic accompaniment.
Comparable difficulty and character — good candidates for what to learn next.
Ballade is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 6.
You should be comfortable at Henle level 4 — meaning you can already play level 3–4 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
Ballade is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include Ballade No.2 by Andrei Anghel, Barcarolle by Anton Stepanovich Arensky, Albumblatt in A minor by Johannes Brahms — see the full similar-pieces list on this page.