This work by Kirnberger showcases the formal rigor of the mid-18th century German style through a set of keyboard variations. It is distinguished by its clean, pedagogical approach to standard Classical variation techniques.
The primary challenge lies in maintaining crisp, even articulation during the passage-work variations.
Comparable difficulty and character — good candidates for what to learn next.
12 Variations on 'Ich schlief da träumte mir', EngK 68 is rated Henle level 3 of 9 — late beginner repertoire, roughly ABRSM grades 4–5. In the RCM system it corresponds to about level 4.
You should be comfortable at Henle level 3 — meaning you can already play level 2–3 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 Variations on 'Ich schlief da träumte mir', EngK 68 lasts about 6 minutes.
12 Variations on 'Ich schlief da träumte mir', EngK 68 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 Allegro fürs Clavier by Johann Philipp Kirnberger, Allegro in A-flat major, EngK 50 by Johann Philipp Kirnberger, Ballet in B major, EngK 82 by Johann Philipp Kirnberger — see the full similar-pieces list on this page.