Alfred Bachelet's approach to the ballade form is rooted in French late-Romantic lyricism. It is characterized by gentle harmonic shifts and a flowing, narrative-driven melody.
Developing a singing tone (cantabile) that sustains through thicker harmonic textures is essential.
Comparable difficulty and character — good candidates for what to learn next.
Ballade 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.
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 16 Waltzes by Johannes Brahms, Belle of the Ball by Leroy Anderson, American Beauty by Joseph Francis Lamb — see the full similar-pieces list on this page.