This is a powerful and demanding sonata movement by Tchaikovsky, reflecting the dramatic intensity and rich Romantic harmonies of his style. It features broad melodic lines and virtuosic passagework, requiring considerable technical command.
Mastering the wide dynamic range, controlling the driving rhythmic energy, and executing the complex chordal passages are significant challenges.
Allegro in C minor is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 9.
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.
A typical performance of Allegro in C minor lasts about 6 minutes.
Allegro in C minor is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.