Coins are the main collectible item in Mushroom Kingdom Fusion. When 100 are collected, an extra life is gained. Sonic and Tails use coins in place of the rings from their games, as they lose all their coins when hit, but cannot die while they still have coins. Unlike most games, coins are not the currency of Mushroom Kingdom Fusion.
In addition to regular gold coins, some levels also have eight red coins scattered about them, disguised as regular coins. Collecting all eight grants an bonus item at the end of the level.
Mushroom Kingdom Coins are no longer always your garden variety coins in all of the Worlds. Coins have a different design for every world. Sometimes, coins will take on a different appearance for a level with a different theme, usually for secret levels.
- In World 2, they are Coins from Metal Slug.
- In World 3, they are Blue Orbs from Mega Man X4. (Orb drops are worth three coins each.)
- In World 4, they turn into Skull Coins from Magic Sword.
- In World 5, they become gemstones.
- In World 6, they are currently undecided.
- In World 7, they are Rings.
- In World 8, they turn into the original coins from Super Mario Bros.
- In World 9, they become the Marathon logo.
The designs for World 0 and World -1 haven't been decided yet.