There are a few,,,
The Bersa thunder 22 is about the same frame size as a Walther PPK,,,
I own and love mine but it's bigger than you are asking about.
There is the
Beretta Bobcat.
The
Taurus PT-22,,,
Essentially a close copy of the Beretta,,,
One of the Mods in this forum has one and says he likes his very much.
The
Taurus 22-PLY,,,
This is the polymer framed version of their PT-22,,,
I own this pistol and it performs flawlessly for me using CCI MiniMags.
I liked mine so much I bought the
.25 ACP version as well.
Hope this helps.
Aarond