Upon entering the game proper you will be able to travel to your right for several screen lengths. Heading right, you will pass a subway entrance. Head down these stairs, and you will see a treasure to your left that you can't reach.
Head right one screen, and feed Blob a Punch jellybean (hole.) Head back to the left, feed Licorice (ladder) to collect your first treasure. Jump down, and run to the right until you see "Sue Baby" graffiti - it should be the last of the red brick area. Use a Punch (Hole) jellybean on the left or right side of the screen, and fall in.
You should be in the first cave screen, with a treasure but a subway serpent guarding it closely. Time your movement as to avoid touching the creature's head as you grab the treasure (or sacrifice a life if you want). Keep holding the umbrella as you continue all the way to the right. Collect the third treasure in the corner. Use the Cinnamon jellybean (blowtorch) to burn the web. Use Vanilla to shield yourself against the falling rocks. At the end, use the Strawberry jellybean to make a bridge across the gap to collect treasure #4. Retract the bridge, and jump down the two-floor gap (no umbrella required for falling two platforms. )
When you move to the right, you should see a diamond in mid-air. Feed a Tangerine (Trampoline) to Blobert when he's directly under the diamond, and bounce to collect the diamond. Once you have it, head to the left corner, use a Punch jellybean to fall down, and continue left. Grab the treasure from the creature. Drop down one more screen, either through the gap to the right, or by creating your own hole.
Walk to the left until you see a ledge. Feed a Licorice bean to climb up the three platforms to get treasure #7. The fastest way down is to feed a Punch bean, and press each time you fall through (which keeps the blob in the hole form).
You should now be at the lowest part of the cave before the water, but you'll need to head left. This should bring you to the central column.
Feed the Tangerine to Blobert in the middle of the colum, and bounce until you can land on the highest platform you can reach (which would be the very-thick one). Head left, and call Blobert with a Ketchup jellybean. You should see the next treasure guarded by the bouncing creature. You can first cross the gap using Strawberry, or simply jump in as the creature is easily avoided. In either case, you will want to use a Punch bean on the left, and drop down to collect three treasures in the row (chaining falls using ). Drop down once more after the third treasure, and move right to get Treasure #11.
Use a Vanilla bean to create an umbrella, and use it to fall down the gap to the left. Reach the bottom-left corner of the large chamber for treasure #12. Move right, and down one screen, and stop before the drop into the water.
Use a Cola (Bubble), and dive into the water. There are eight treasures here - one diamond hiding on the ceiling to the left, six diamonds hiding on the top right of the underwater section, and one treasure chest on the right hand side in a bed of stalagmites. The diamonds are easy to claim, but the treasure chest requires careful navigation to avoid losing a life. (You can optionally ram the stalagmite if you collected all the underwater treasure). You should have 20 treasures so far.
To exit the underwater area, surface and head to the left. The bubble should move you to dry land, where you can use a Licorice followed by a Strawberry. When you're below the gap for the large chasm, use a Tangerine just outside of the lower left ledge (you can use a cinnamon bean for precise placement), and bounce to the top and exit left. Use Licorice to climb up two platforms, and place a Tangerine slightly past the third ledge up - if placed right, you can get a diamond, and fall onto the platform to the right. Use a Ketchup bean, and continue to the right where you can use licorice to return to the subway level.
Use Licorice to reach the upper floor, but head to the left first to collect the last treasure. Return right, use Strawberry to cross the gap. To exit, feed an Apple jellybean (jack) to lift the sewer grate, and licorice to climb out.
Head all the way to the right to reach the health food store. If you collected enough treasures, you should have more than enough vitamins. Purchase them, and use a Root Beer jellybean to rocket over to Blobolonia.
Move two screens right. Once you reach the first set of trees, you will see balls bouncing up and down. Time your movements and walk past the balls as they're in the air. Once you reach the clearing, you must feed the Orange jellybean before going to the next screen.
At the second forest, you will see cherry bombs. You must shoot them before they hit the ground, as their explosions will cost a life even if you are on a different screen. It is possible to run past the first two sets, but the third set must be destroyed.
At the corn field, there will be four screens of dodging popcorn. At the third screen, hold your fire until you see a gap in the pattern, then shoot and run your way past. On the fourth screen, run to the middle, wait for a gap, and continue running with the gap in the right position.
Next is the factory, with four screens. If you take the direct route, you will need to shoot the falling balls until the machine breaks down. This will need to be done twice.
Continue right. You will see sweet teeth trying to crush you, but their pattern is easily dodged as the teeth only fall at set times.
One screen after the second set of teeth (before the line of chocolate), use a punch bean in the middle, and walk to the right. Turn the machine off, use a licorice to return to the floor above, and Strawberry to cross the gap.
Proceed to the end of the corridor - there's only two more sets of sweet teeth.
At the end of the corridor, feed a lime jellybean to make a key, and unlock the door.
In the last room, you need to feed Blobert an apple jellybean. However, he's out of normal throwing range. To get around this limitation, you need to rapidly move left and right to trick the game into thinking you're running, and throw the jellybean as you are moving right.