Gloomhaven: Buttons & Bugs is a solo play game, with an original campaign story written by Isaac Childres, contains features a playstyle similar to Gloomhaven in a fraction of the size.

Gloomhaven: Buttons & Bugs takes place after the events of Gloomhaven and Forgotten Circles. The Aesther recluse Hail has earned a reputation for being highly instrumental in saving the city from disasters, and she absolutely hates it. Wannabe heroes are constantly interrupting her studies at the Crooked Bone, looking for help in becoming famous themselves — not to mention all the demons that come by looking for vengeance. She briefly thought about moving, but as that would require effort, she instead just placed an enchantment on her front door: Anyone who attempts to open it becomes miniaturized and therefore is no longer a problem.

Your character is one of these wannabe hero. In an ill-advised attempt at fame, they attempt to visit Hail, and poof. Now they are the size of a mouse and have entered an entirely different realm of lawlessness and self-preservation. They must discover a new way into the Crooked Bone to convince Hail to return them to their previous size.

Each scenario consists of a single card, pitting one mercenary against a handful of enemies with simplified actions and AI. Each mercenary has a hand of only four double-sided cards, but they can be used twice — both the front and the back — before they are discarded. Attacks are resolved using dice in conjunction with a modifier table, and both the table and the mercenary ability cards can be improved as you level up throughout the campaign.