Nino Rota's wonderful 15 preludes! Only a couple page each, they present colorful and contrasting material.
Some Rzewski's works (Nanosonatas, etc.) are quite short, quirk and interesting. On IMSLP you can find recording and manuscripts in public domain -quite strange for a living composer!-
Zaderatsky wrote 24 Preludes, more extended than Shosta's but you can easily make a selection. You can find them in Youtube or (all) in Spotify. Liadov wrote some of the most enchanting miniatures of the Russian school. Often grouped in smaller sets, Biriulki could be your choice.
In the Romantic period, small pieces cycles by Schumann and Grieg are a very famous choice. Baroque music is a treasure trove of miniatures, but OT

Last, I suggest you to have a look at the album "85 Piano Miniatures" by Matthias Veit, rich of wonderful ideas.