I have a number of atomic chess endgame studies (see my lichess studies... studies of studies?), some orthodox proof games and retros, and some slightly odder ones. Here's one of my better attempts.
Phénix 287 (July-August 2018)
Add a black queen for a PG 9.5 (add a black queen somewhere, then reach the resulting position after white's 10th move)
lichess.org/editor/rnb1kbnr/p3pppp/8/8/2P3P1/2N2N2/PP2PPB1/R2QR1K1_w_-_-_0_1
Phénix 287 (July-August 2018)
Add a black queen for a PG 9.5 (add a black queen somewhere, then reach the resulting position after white's 10th move)
lichess.org/editor/rnb1kbnr/p3pppp/8/8/2P3P1/2N2N2/PP2PPB1/R2QR1K1_w_-_-_0_1