-Collect 1000 marbles and complete the game with a Smart Superhero rank to unlock Earthworm Kim. The difficulty of the game increases when played as Earthworm Kim.
-Head to the Fear part of the Brain and enter the door on the right of the Sacred Cow Of Contemplation. In this room is the way to the levels Poultryguyst and Poulrtyguyst 2. There is a door blocked by a metal gate. If you have all 1,000 marbles and have beaten Earthworm Kim, the gate will open. Walk through it and the game will automatically reset. When the game is started again, Earthworm Jim usually hops around playing the accordion -- this time Kim will be the playing it and will soon be smashed by a cow. Press any button to get to the file select screen. You should now have a fourth file as Earthworm Kim.
There is a building shaped like the back of a cow in the fantasy part of the brain. Inside, you must ride an annoying ice cube around a room. If you fall off, you have to start over. However, if you jump onto the ice cube and immediately jump back onto the fridge, then you can just watch the ice cube slide around. Just jump back onto the ice cube once it returns to the fridge but before it stops moving. You will receive a golden udder without doing any work.
-Go outside the entrance to "Hungry Tonight?", then collect the Power Parp Tin from Snott and use it to collect the nearby extra life. Enter "Hungry Tonight?" and quickly exit. Talk to Snott again to get another Power Parp Tin, then collect the extra life again. Repeat this to get as many extra lives as necessary.
-In Memory, go to Barn To Be Wild. Cross the river of quicksand, then go around the corner to the large bed of quicksand with rocks, pigs, and crates floating in it. Wade over to the first rock, then jump across the green bobbing crates. Go over to the second rock to find an entrance on the wall. Move the camera around if you cannot see it. Jump and hover over to it, then wade the rest of the way. Enter, and there will be an extra life for you. Collect it and go back to the entrance/exit of the level. Re-enter it to get more lives. If you have suffered damage and need more health, pause game play and select "Save and go to brain". You will return to brain central with full health and all the lives you have gathered. Only use "Save and go to brain" if you have suffered damage and are almost dead; it will take much more time to get the lives you want. Repeat this for some time and eventually you will have plenty of lives for Psycrow.
Ignore the marbles, gather bullets at all times, and shoot him. Keep his marble level at 0 or close to it at all times. This allows you to get your marble level up to approximately 85 within a couple minutes.