In KO Heroes, the five Gameboy-like cartridge cards are laid out in the middle of the playing area. Players take turns flipping over the top card of a deck, with each card showing either a mirror, a potion, or a map printed on the back. The action that players take depends on the target card revealed and what's on top of the deck:
If the top card shows a mirror, slap the card with the same character type as the target.
If the top card shows a potion, slap the ca with the same character color as the target.
If the top card shows a map, slap the card with the same background landscape as the target.
Whoever slaps the proper cartridge card first claims the card just flipped over. After the deck runs out, whoever has collected the most cards wins!