Dinky Dungeons is a bare-bones role-playing game published by "Doc's Games - an Uncle Morty Production." The game is very small in size and all contained in a tiny plastic bag a few inches across and down. The rulebook, a Game Master screen, an (incomplete) errata list, an adventure, a map and character sheets were all included in the baggie - with two 5mm dice rounding out the package
The gameplay is about as simple as can be - characters have two attributes ("Physical" and "Mental") but they go pretty far with very little. Standard RPG stuff like character classes/races and equipment are included plus a nice selection of monsters and pretty extensive rules for regular RPG play like magic systems, skills rolls and saving throws. It's impressive for such a small package. They even have a great but stupid race called Fuzzy Winkers (undesirable rodents that are just bad characters, period) to add to the fun.
Dinky Dungeons had a number of additional supplements and even a Sci-Fi version.