So in this guide I'm going to show screenshots for the location of every heart in the game and give a brief description of how to get the heart. I'll be putting the hearts in order of when you might come across them in a standard playthrough and state any items required to get the heart.
If you need help finding specific items, please look at my other guide:
Solution for COLLECTOR In MINITHeart 1: Water Flower - Watering CanOne screen west of your starting house is a flower growing in a field. You'll need to water the flower and respawn three times for the flower to grow completely and give you a heart.
Heart 2: Defeat Bull - No RequirementsWhile traveling to the Desert Campsite you'll come across a charging bull. Defeat the bull and he'll drop a heart.
Heart 3: Hidden in Graveyard - No RequirementsIn the Graveyard near the Hotel you'll see a heart near a tombstone. There's a fake wall you can push into to clear a path to the heart.
Heart 4: Give the Bone to Your Dog - No Requirements (Basement Key helps)Grab the Bone in the Graveyard north of the Hotel. Travel to your Starting House and give the Bone to your Dog. He'll give you a heart as a present.
Heart 5: Lost Temple South - Fast ShoesLost Temple South is a really long maze. The only way to get through it is to rush through with the Fast Shoes. Even with the Fast Shoes you'll barely make it so you'll have to avoid hitting as many walls as possible so you can keep charging.
Heart 6: Purchase in Basement of Sneaker Hut - All 19 CoinsOnce you collect all 19 coins you can purchase the final heart in the basement of the Sneaker Hut.
If you need help finding all the coins, please check out my other guide:
Solution for TREASURE HOARDER In MINIT