Emile-Robert Blanchet was a Swiss composer whose style bridges late Romanticism and early Impressionism. His ballade contains sophisticated harmonic language and nuanced dynamic requirements.
The player needs a highly refined sense of color and touch to bring out the subtle harmonic inner voices.
Comparable difficulty and character — good candidates for what to learn next.
Ballade No.1 (Op.29) is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8.
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.
Ballade No.1 (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 Ballade No.2 by Emile-Robert Blanchet, Ballade No.3 by Emile-Robert Blanchet, Ballade by Germaine Tailleferre — see the full similar-pieces list on this page.