Haydn's keyboard sonatas are vital examples of the evolution of the form, characterized by their wit and inventive development. This work showcases his mastery of motive-based composition.
Executing the subtle ornamentation with grace without disrupting the pulse is the main difficulty.
Comparable difficulty and character — good candidates for what to learn next.
Keyboard Sonata in E-flat major is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 8.
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 Keyboard Sonata in E-flat major lasts about 8 minutes.
Keyboard Sonata in E-flat major 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 Bergamasca by Girolamo Frescobaldi, Caprice et Sonate by Johann Wilhelm Hässler, Capriccio di obligo di cantare la quinta parte, F 4.11 by Girolamo Frescobaldi — see the full similar-pieces list on this page.