Hugh McAmis, primarily an organist, composed this work with a sophisticated use of sonority. It relies on subtle color changes and voicing to achieve its evocative effect.
At Henle 4 this is an intermediate piece that expects secure technique and real attention to phrasing. The main demands: chord voicing — bringing out one note inside a handful of others; careful pedaling — clarity depends on the foot as much as the fingers; and several simultaneous layers, each needing its own dynamic level.
The main difficulty is managing complex pedal changes to sustain harmonic colors without blurring the lines.
Comparable difficulty and character — good candidates for what to learn next.
A level or two down with the same spirit — ideal if this piece is still out of reach.
Where this piece's skills lead: slightly harder works making similar technical demands.
Dreams is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 6.
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 Dreams lasts about 3 minutes.
Dreams 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 Clair de lune - piano by Claude Debussy, Gymnopédie No. 1 by Erik Satie, La cathédrale engloutie by Claude Debussy — see the full similar-pieces list on this page.