This is a non-collectible reworking of the CCG XXXenophile. While XXXenophile's theme and artwork were rated R, Girl Genius can be played by families without grandma getting embarrassed. (However, a couple cards do feature scantily dressed women.)
Each player gets a five-card hand and 12 cards are laid out face-down in a patchwork pattern. Each card has colored symbols along each side, a point value, and special instructions. On your turn, you turn over one face-down card then spin any face-up card 180 degrees. After spinning, if any of the symbols on the edges of the spun card match the symbols on one or more of the surrounding cards, you "pop" the card(s) with the most matching symbols. "Popping" a card means you must follow the instructions on the card (whether helpful or harmful) and then (usually) add it to your score pile. Cards in your hand are used to replace any popped cards. The game is played until one player has 100 points or has captured a combination of submarine and dirigible cards.
Unlike most of Cheapass Games's games, this one is professionally manufactured with full color, laminated cards with rounded corners.