It isn't to everyone's taste, especially since the list of changes is immense, but it includes drivable vehicles, sleep, alcoholism, and reworked NPC behaviour. It's a comprehensive, colossal piece of compilation modding, much of it done by the author, and the rest factored in from across the community. For Shadow Of Chernobyl there's pretty much a one-stop shop for changes, which is the extraordinary Oblivion Lost mod. The past week of my gaming time has been dominated by Stalker mods: downloading, testing, crashing, deleting, reinstalling, and even a few hours of playing.