Tim Schafer's classic point-and-click biker adventure Full Throttle is currently free on GOG.
Released back in 1995, Full Throttle was Schafer's first solo project at revered point-and-click developer LucasArts, having previously co-designed Day of the Tentacle with Dave Grossman and co-written The Secret of Monkey Island and its sequel with Grossman and Ron Gilbert.
While Full Throttle retained the comedy abundant in Schafer's previous work, it was considerably less romp-y than its forebears, mixing its humour with a touch of post-apocalyptic grit - although it's technically only set in a more desolate version of our world.