I vibe-ported xpenguins[1] to Web[2] recently, can be used as bookmarklet and let run on any website. No original Lemmings in that one however, only the knockoff penguins.

[1] http://xpenguins.seul.org/ and updated at https://github.com/Grumbel/xpenguins-ng

[2] https://xpenguins-web.github.io/