Many of people in the Internet Archive post their childhood game dumps (rips) as free to play games (which runs on M.A.M.E. (Multiple Arcade Machine Emulator)). The most frequent Lemmings game archiver is Cloudoraemon (who goes by the name of CloudyEgg), who archived the Nintendo Game Boy version, the Macintosh II version, and the VGA, EGA, Tandy, and CGA version of the DOS version. Some Lemmings games on the Internet Archive are cracked. He also put The Tomato Watcher's improvement of the Nintendo Entertainment System version (NTSC) of Lemmings.
Links: https://archive.org/search?query=Lemmings&and%5B%5D=mediatype%3A%22software%22 (Lemmings games), https://archive.org/details/LEMMING (VGA version)