Cramer's Op. 35 sonatas represent a mature stage of his compositional style, offering greater technical challenges and deeper musical expression. They are refined examples of Classical sonata writing.
Demands refined control over voicing, dynamic shaping, and articulation for expressive phrasing.
3 Sonatas (op.35) is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 8.
You should be comfortable at Henle level 6 — meaning you can already play level 5–6 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
3 Sonatas (op.35) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.