BiPolar Melodies is a reflective contemporary piece characterizing contrasting emotional states through melodic development. It is notable for its shifts in intensity and harmonic color.
Focus on the subtle voicing required to balance the shifting emotional moods between the hands.
Comparable difficulty and character — good candidates for what to learn next.
BiPolar Melodies (Op.11 No.21) is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 5.
You should be comfortable at Henle level 4 — meaning you can already play level 3–4 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 BiPolar Melodies (Op.11 No.21) lasts about 3 minutes.
BiPolar Melodies (Op.11 No.21) 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 Cambios sinfónicos in E major by Srikanth CR, Body and Soul by Johnny Green, Fantasy in D minor by Wolfgang Amadeus Mozart — see the full similar-pieces list on this page.