Earthworm Jim 2 follows the exploits of annelid superhero Jim and his new sidekick Snott as they try to rescue Jim's beloved Princess What's-Her-Name from a forced marriage to the nefarious Psy-Crow. While chasing Psy-Crow across the universe, Jim comes across the summer homes of a number of villains from the first game, including Major Mucus, Evil the Cat and Bob the Killer Goldfish.
Like the original game, Earthworm Jim 2 contains a lot of irreverent, surrealist humor. It also features more diverse gameplay than the original, with each stage having a unique different style and mission, often with varied gameplay and objectives to complete from stage to stage, as well as various new weapons to obtain and use.
There are extra weapons in addition to the Plasma Blaster, such as the Three-Finger Gun, the Electro-Gun, Homing Missiles, the extremely powerful Barn Blaster, and the rather useless Bubble Gun. Snott returns from his cameos in the first game, and is now a permanent companion for Jim, hiding in the backpack of Jim's Super Suit. Snott can be used to stick and swing to other slimy green surfaces, or as a parachute, upon jumping.