Henning Mankell (the Swedish composer, not the novelist) wrote evocative piano music deeply rooted in Scandinavian Romanticism. His ballades are known for their somber, folk-inspired melodic qualities.
Achieving a warm, resonant tone color across the entire keyboard register is essential for this piece.
Comparable difficulty and character — good candidates for what to learn next.
Ballade No. 1 is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 7.
You should be comfortable at Henle level 5 — meaning you can already play level 4–5 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
A typical performance of Ballade No. 1 lasts about 4 minutes.
Ballade No. 1 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.5 by Henning Mankell, Ballade No.2 by Henning Mankell, Ballade No.1 by Henning Mankell — see the full similar-pieces list on this page.