These variations represent a virtuosic expansion on Paganini's famous theme by the Italian composer Rosario Scalero. The work serves as a challenging technical display piece characteristic of late Romantic pedagogical writing.
The primary challenge lies in the rapid scalar passages and the precision required for the shifting figurations across the keyboard.
Comparable difficulty and character — good candidates for what to learn next.
12 Variationen nach Paganini (Op.14) is rated Henle level 7 of 9 — late advanced repertoire, roughly ABRSM grade 8 and above. In the RCM system it corresponds to about level 10.
You should be comfortable at Henle level 7 — meaning you can already play level 6–7 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 12 Variationen nach Paganini (Op.14) lasts about 8 minutes.
12 Variationen nach Paganini (Op.14) 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 14 Variationen by Rosario Scalero, Bourrée fantasque by Emmanuel Chabrier, Wanderer Fantasy in C major by Franz Schubert — see the full similar-pieces list on this page.