This is a pedagogical set of variations on a famous German folk melody. The work is distinctive for how Gurlitt adapts a simple tune into various technical patterns common in beginner repertoire.
The student needs to maintain steady, even playing across the different textures used in the variations.
Comparable difficulty and character — good candidates for what to learn next.
'Ach du lieber Augustin' (Op.115) is rated Henle level 2 of 9 — beginner repertoire, roughly ABRSM grades 2–3. In the RCM system it corresponds to about level 3.
You should be comfortable at Henle level 2 — meaning you can already play level 1–2 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 'Ach du lieber Augustin' (Op.115) lasts about 2 minutes.
'Ach du lieber Augustin' (Op.115) 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 Blumenwalzer by Léon Jessel, Bluin' the Blues by Henry Ragas, Bohemia by Joseph Francis Lamb — see the full similar-pieces list on this page.