This is a minor Romantic character piece likely influenced by the mid-19th-century salon style. It is characterized by its song-like melody and modest harmonic structure.
The primary challenge is maintaining a consistent singing tone while balancing the inner voicing against the melody.
Comparable difficulty and character — good candidates for what to learn next.
Auf einer Burg (Op.58) 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.
A typical performance of Auf einer Burg (Op.58) lasts about 3 minutes.
Auf einer Burg (Op.58) 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 by Heinrich Neal, 'O sole mio by Eduardo Di Capua, Belle of the Ball by Leroy Anderson — see the full similar-pieces list on this page.