Flower 4 (27)

You'll start by dropping through some bumpers. Keep heading right until you reach the end of this section. Go through another set of bumpers, jump over those spiky enemies (watch out!), and then head down the pipe.

You're now in a new room where the water level goes up and down. When the water starts to fall, make your way to the left side of the room. Grab all the coins you see, and be sure to snag the first red coin (that's #12!) in this area. Once the water rises again, head back to the right. Hit the egg block to restock your eggs – you'll need 'em!

Keep going right past the Stork Stop. You'll see a thin column just to its right. Jump to the right of that column. As the water level drops, look for some soft blocks. Ground pound through them to find another red coin (#13) nestled right in between.

Continue to the large area on the far right. Head up the ledges, taking out any Piranha Plants that get in your way. At the very top, you'll spot an arrow pointing up into a narrow alcove. Here's a neat trick: drop down to the thin platform directly below that arrow. Now, shoot an egg straight up into the alcove. It'll ricochet and grab you three more red coins (that's #14, #15, and #16!).

With those collected, head right and drop back into the water that's rising and falling. This time, stick to the left side by the wall. As the water sinks, follow it down a narrow passage to grab another red coin at the very bottom (#17). When the water rises, head right again. Wait for the water to fall once more, and then jump to avoid a rotating spiked pillar. Grab the red coin (#18) at the bottom of this section.

Now, let the water rise again and head right. You'll need to jump onto a couple of thin ledges. To the right of these ledges, you'll see a block you can pound through.

Head into this new area and keep going right. Collect all the coins between the pillars – make sure you get the last two red coins here (#19 and #20!). When the water starts to rise, get to the absolute rightmost point you can. Wait for the water to fall again. As it recedes, pound through some more dirt and you'll find the Flower you're looking for in the opening!