Fun! Wasn't on the other submission, a list of retro Polish games. Maybe it doesn't qualify as retro though.
Sadist (and its sequels) was little-heard of among the Polish gamers of the late 90s and early 2000s, but it did manage to amass something of a cult following. IIRC there was a small but vibrant forum in its heyday, and the game's online fanbook (now read-only) has 700+ entries.
The author, Grzegorz 'GAD' Drozd, was a frequent poster to pl.comp.lang.pascal in its heyday. In addition to Sadist, he also produced many other DOS and Windows freeware games, most of them single-handedly. His site (gadz.pl) is well worth checking out.