Back in the abandoned 2.10.x branch a programmer called Michael Mann contributed a new Simple Simon move function that allowed it to solve more games. In 2.34.0 this move function was restored, and made optional. We now have a theme called "the-last-mohican" (or "tlm" for short), after the movie "The Last of the Mohicans" by a different Michael Mann, which I have watched and enjoyed, that is capable of solving over 90% of the first 5,000 PySol Simple Simon deals. (Incidentally "The Last Mohican" is the direct translation of the book and movie's name in Hebrew). The solutions of the solver were verified to be correct using Games-Solitaire-Verify.
Working on this theme uncovered a bug in the solver where the --next-instance flag was removed by accident, and it is now fixed.
Aside from that, there's now an improved atomic moves theme - "toons-for-twenty-somethings", which can solve all of MS Freecell's 32,000 deals. It is still much slower than the meta-moves-based theme.
There are also some other more minor changes, which can be found at the NEWS file in the distribution.