Ernst Heuser's composition is a late-Romantic take on the bolero genre, utilizing stronger dynamic contrasts and heavier textures. It moves away from the salon style into more substantial programmatic piano writing.
Focus on projecting the primary theme through the busier accompanying figures.
Comparable difficulty and character — good candidates for what to learn next.
Bolero is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 5.
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 Bolero lasts about 4 minutes.
Bolero 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 Albumblatt by Ernst Heuser, Solfegetto in C minor, H 220 by Carl Philipp Emanuel Bach, Allegro in D minor by George Frideric Handel — see the full similar-pieces list on this page.