Heart #1 – World 1-2
With the fan removed and the wind settled, head back to the Toad who is now crying over his torn up flower bed. Enter Paperize mode and place three Fire or Ice Flower Stickers in the desired locations. The Toad will rejoice and give you a HP-UP Heart, as well as double the stickers you placed.
Heart #2 – World 1-4
This is the only mandatory HP-UP Heart in the game. After placing the Warp Pipe in the underground level, you will be ambushed by a Big Buzzy Beetle. Defeat it to get the HP-Up Heart.
Heart #3 – Surfshine Harbor
Enter Surfshine Harbor and head to the third building. Enter Paperize mode and have the door placed in the correct position. Enter the room and head out the back door. From there, head right an enter the next door. Inside, hop up the crates and you will find the HP-UP Heart in the last room on your right.
Heart #4 – World 2-1
When you reach the top of the pyramid at the end of the level, move up the stairs on your left and slide down the ramp. From here, hop onto the next platform to reach the HP-UP Heart.
Heart #5 – World 2-2
At the top of the Yoshi Sphinx where the piece of the Sticker Comet rests, move north despite the lack of a path. You will fall of the sphinx and onto a platform down below that contains the HP-UP Heart.
Heart #6 – World 2-3
From the start of the underground maze, head down the slide on the right, and again down the next slide on the right. Enter the door and open the third coffin from the left to find the HP-UP Heart inside.
Heart #7 – World 3-1
This HP-UP Heart is fairly simple. Go through the entire level and you should find the HP-UP Heart waiting in front of the piece of the Sticker Comet.
Heart #8 – World 3-3
Starting from the base of Wiggler’s Tree House, head up the stairs and into the room with the table and the firplace. On the right side of the room, place a Secret Door Sticker on the wall to find an HP-UP heart inside.
Heart #9 – World 3-8
Move into the second area and get to the right of the first large tree. Hop onto the farthest back ledge and move left to enter a cave with the HP-UP Heart waiting inside. Completing World 3-12 first will make this easier.
Heart #10 – World 3-9
In the second area, you will notice an area pointing towards the wall in the area where the poison used to be. Follow the area and enter the hold in the wall to find the HP-UP Heart. This HP-UP Heart can be grabbed before completing World 3-12, but it will be much harder since the poison will surround the arrow and the entrance.
Heart #11 – World 3-10
Play through Snifit or Whifit one more time after you have played through it once. The HP-UP Heart will be waiting in the bottom room where the piece of the Sticker Comet is. You do not need to play the bonus game at the end to get the HP-UP Heart.
Heart #12 – World 4-2
As you are running up the frozen the second time, you should notice the HP-UP Heart on a ledge on your right. Pass it and you will eventually see a point where you can hop onto a lower part of the ledge. Jump on and head right to grab the HP-UP Heart.
Heart #13 – World 4-3
Return to the mansion and head into the lobby, the room to the left of the main entrance room. Instead of the Purple Toad lounging on the sofa, the former steward will be sipping away tea in his place. Sit on the chair to receive the HP-UP Heart and warm cup of tea.
Heart #14 – World 5-1
Head into the right exit from the main area with the piece of the Sticker Comet. Instead of whacking the big red flower, walk behind it and move to the right to find a secret hole in the wall. An HP-UP Heart waits inside.
Heart #15 – World 5-6
Right before your fight with Petey Piranha, there will be an HP-UP Heart to left of the moving platform with the Chain Chomps. This one is in plain site and hard to miss.
Heart #16 – Decalburg
After saving the Adventure Toad in the five different worlds, head back to Decalburg and head into the residential section. Enter the last house in the area to find a room with five different postcards from each of the worlds that were sent to the Toad inside the house. Read all five postcards and the Toad will burst into tears, giving you the last HP-UP Heart.
The Adventure Toad must be found in each of the five worlds. Mario must save him from two enemies each time. His locations:
- In World 1-1, in the area north of the area where the fan blew.
- In World 2-1, in the area after the cave.
- In World 3-11, right next to hole hidden in poison.
- In World 4-6, on the left of the long line of Shy Guys and Snifits.
- In World 5-2, on the bank of the river. To reach him, head left from the end of the level and follow the path.