Clockwork is a rhythmic, motoric work that exploits the percussive nature of the piano. Its distinctive quality lies in its precise, mechanical rhythmic drive that contrasts with sudden shifts in dynamic texture.
The main difficulty is maintaining absolute rhythmic consistency and clarity in the rapid, recurring motifs.
Comparable difficulty and character — good candidates for what to learn next.
'Clockwork' for Winds and Piano (Op. 2) 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.
A typical performance of 'Clockwork' for Winds and Piano (Op. 2) lasts about 4 minutes.
'Clockwork' for Winds and Piano (Op. 2) 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 Keyboard Sonata in D minor by Domenico Scarlatti, Partita No. 1 in B-flat major by Johann Sebastian Bach, Bugatti Step by Jaroslav Ježek — see the full similar-pieces list on this page.