In SpongeBob's dream, you are in a race. First, you have to first complete a lap on a race course dotted with enemies, including tires, oil cans and ferocious cones. Then in his nightmare, you have to try to navigate and get out of the Jellyship and sneak past the Jelly Guards and get the net from Gary.
In Patrick's dream, you take place in Downtown Bikini Bottom. First, you have to defeat the Door-to-Door Salesmen, Dental Hygienists, and Personal Trainers in Bikini Bottom. Then, you have to shoot the Flying Clowns and battle a Clown. Then, you have to navigate through Patrick's house without his superpowers and defeat the Dreaded Patrick.
In Plankton's dream, you take place in Bikini Bottom. First, you have to destroy the Buildings, Homes, Krabs, Krusty Krab, and Barg 'N Mart. Next, you have to get yourself with other plankton with you, out of a Sperm Whale. The other plankton will die after an enemy kills them. They will get up after a short while. You must navigate your way out of the Whale by defeating Fishbones, Guitarfish, Skitters, and Bonepits.
Evil Tires - They are common enemies in the game.
Major Tires - Bigger than the Evil Tire, Major Treads are tougher. There is another variety called a Monster Tire.
Oil Cans - This enemy will shoot oil.
Giant Oil Cans - Bigger than the Oil Cans, Oil Drums are tougher. There is a bigger one called an Oil Vat. Take out his friends and then him.
Caution Cones* - This enemy is undefeatable.
Jellyfish - There are two types. Pink ones are the only jellies caught in nets. Big green Jellies are undefeatable and will get angry when hit.
Door to Door Salesmen - These Starfish can throw clothes at you.
Dental Hygienists - This Starfish will throw toothpaste at you.
Bodybuilders - There are three types. One doesn't throw dumbbells. One throws dumbbells. One is a Buff Trainer.
Clowns - There are two clowns. One of them that fly and shoot balls and one acts as a boss.
Soap Scum* (unless Patrick has the Soap Box) - This enemy is only defeatable when Patrick has the Soapbox.
Lint Worm - This is a common enemy in the game.
Plungers* - These enemies are undefeatable.
Dirty Clothes (Filthy Pile) - This pile of dirty clothes will shoot at Patrick.
Dreaded Patrick - The ruler of Garbageland. Keep shooting him and avoiding the dirt until he falls down.
Buildings - They are common enemies in Plankton's good dream.
Helicopters - This enemy can only be defeated by lasers.
Houses - There are three: SpongeBob, Squidward, and Patrick. They take one hit like a Building.
Krusty Krab - Same as the other buildings.
Krabzilla - Mr. Krabs is a Giant. Kill him to save time or just ignore him.
Tank - They can shoot Plankton. Destroy them by walking into them.
Barg 'N Mart - Same as Krusty Krab and the other houses.
Skelefish - They are Fishbones in the whale's mouth. Kill them. There are smaller versions of them.
Bone Pile - If you don't kill the bone pile, it'll summon small Skelefish. Kill it to prevent the fish from coming.
Shark Ray - They are based on Guitarfish inside Plankton's nightmare.
Skitters - They are Sea Spiders inside Plankton's nightmare.
Note: The * indicates the enemy you can't kill.
In Patrick's dream, most of the enemies were starfish.