Mines are hazards in the Quack Series. They're purple colored blocks that may start blinking when Crackle is near them, blink noise will start getting faster and faster. After a little while of blinking they'll explode and if Crackle is near he may automatically die, forcing the player to restart the level. They have 2 variants that are the normal mines and spiked mines. If they blow up they cannot regenerate.
Normal mines are mines with nothing covering them around them. They are a bit less dangerous than the spiked ones because the player can cross through blocks with no danger at all. They may explode instantly if Crackle touches them, as well when Crackle lasts too long near them.
Spiked Mines are mines that include spikes around them. They're very dangerous because the player is forced not to touch any walls when walking through 2 walls with Spiked mines at both sides. Otherways, the player will lose one life, not only for touching the spikes, they will also blow up if Crackle touches the square inside. They're encountered in most levels in the game.
The oddest thing about both kinds of mines is that if Crackle is armed with bullets and he shoots bullets to any Mine, the mine may end up exploding and killing and destroying all the sprites in the level, including Crackle himself. It's unknown why the mines have been made that dangerous.