Walk around the fence to the scarecrow. Press 'B' and learn how to use the "context-sensitive" button.
When no longer drunk, swim across, and jump from platform to platform.
Climb until you reach a lever. Pull it and enter the door shown below.
Try pressing 'B' to get the key. Eventually, a cutscene will mention that you're forgetting something, after which you can press 'B' to swing a frying pan. Get the key, and unlock the door.
Head to the gargoyle, and hit him with the frying pan.
Climb to the platform above, and press B to blast away the boulder.
Speak to the metal crate next to the barn. Then run to the left and speak with Burt who will open a gate for you. Knock out a piece of cheese and bring it to the rat near the crate. Repeat this three times to get the larger crate onto the ground, allowing you to open the barn from the top. You will also collect $100.
You can jump along the rocks around the cheese farm. When you see the light bulb, press B to smash open a rock, revealing 10 extra lives.
Enter the barn, and get the pitchfork to destroy the stacks of hay. To do this, stand between the pitchfork and a stack of hay, and jump just before he attacks. When they're all destroyed, you can pull the lever to open the door again.
Enter the barn from the upper route that was opened. Run across the beams (pressing B to torch bats about to attack, or jump across if going for speed). At the 'B' platform, you can throw knives at the pitchfork to get him down.
Ride the pitchfork, and attack the large haystack. After two hits, it will try pounding the ground when you approach. When it takes four hits, it will smash the ground to an area below.
The haystack is now a robot. It will fire two rockets, which are dodged by jumping. Try to get the rockets to hit the pillars on the side, allowing water to spray. Get behind the piller to get the robot to approach, and have it shocked by the water. When it does, approach, jump, and press B to press the "Do not push" button. Repeat this three times to defeat it.
When it is defeated, water will begin to fill the chamber. Climb up the ladder quickly before the wires contact the water. stand on the 'B', and throw knives at the wires - you will know one is contacting the wire when the music is a bit more intense. There are two locations to throw knives within this area.
Jump on the stone, and collect $100. Ecit, and climb up the ladders, avoiding the wasps. Press B after jumping off the plank, to open a grate below. Collect $100 from here as well.
Find the tickle bees and bring them to the sunflower. They can be found:
Near the wooden crate
Near the cheese area
Near the entrance
On the roof of the barn (where you first open the doors)
On the barrel above the barn. (You may need to crouch-jump to reach the upper part of the roof.)
After getting the bees to the sunflower, jump on the sunflower twice to collect $100.