Akimenko was a student of Rimsky-Korsakov and a teacher of Stravinsky, and this Berceuse displays a sophisticated harmonic language. The piece is distinct for its lush, late-Romantic textures infused with early 20th-century Russian introspection.
Mastering the control of the inner voices within the complex, layered texture is essential for this piece.
Comparable difficulty and character — good candidates for what to learn next.
Berceuse (Op.15) 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 Berceuse (Op.15) lasts about 4 minutes.
Berceuse (Op.15) 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 By the Fireside by Theodore Akimenko, Au Coin de Feu by Theodore Akimenko, Ballade by Theodore Akimenko — see the full similar-pieces list on this page.