Vincent Adler was a Hungarian pianist and composer whose works often mirrored the virtuosity of the Lisztian school. This Ballade displays dramatic keyboard writing and intense thematic development.
Focus on the execution of bravura octave passages and balancing intensity without sacrificing tone quality.
Comparable difficulty and character — good candidates for what to learn next.
Ballade (Op.29) is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 8.
You should be comfortable at Henle level 6 — meaning you can already play level 5–6 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 (Op.29) lasts about 5 minutes.
Ballade (Op.29) 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 Allegro de Concert pour piano by Vincent Adler, Allegro de concert by Vincent Adler, Ballade pour piano by Vincent Adler — see the full similar-pieces list on this page.