Gives off an unusually wet/slimy impression, especially if the various characters (or even places) drool, ooze or otherwise secrete liquids or slime a lot.
Alternate name: Wet and slimy
The first video game about Slobbery was released on March 3, 1993.
Wet here refers to general wet sheen, not pools of water, waterfalls, rivulets, and such. Nor should instances better described as watery be included (unless it still manages to pull of exceptionally slimy impression).
Probably exists in mostly horror themed games as this is a way to make the surroundings and beings seem more alien, as there aren't really that many commonly visited natural places that are slimy and wet, and beings that are naturally slimy/wet tend to arouse fear or revulsion (slugs and such, many unknown marine animals as well).