This work by Marianus Stecher reflects the late 18th-century style of combining variation form with a concluding Rondo. It is an excellent example of Classical-era didactic piano literature.
The focus should be on clean articulation of the light, Classical-style ornamentation.
Comparable difficulty and character — good candidates for what to learn next.
12 Variations and a Rondo (Op.6) 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 12 Variations and a Rondo (Op.6) lasts about 8 minutes.
12 Variations and a Rondo (Op.6) 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 The Entertainer by Scott Joplin, 12 Variations on "Ah vous dirais-je, Maman" by Wolfgang Amadeus Mozart, Piano Sonata No. 11 in A major by Wolfgang Amadeus Mozart — see the full similar-pieces list on this page.