Diamond Mine is the thirty-third level of Even More Bloons.
To complete this level, you need to pop at least two Rainbow Bloons (without hitting the Lightsaber Bloon), then use the last dart to pop the Ice Bloon, which will freeze at least Rainbow Bloon. The same dart should pop the Spiky Bloon. This may take multiple tries.
- Hence the level's name, it may mean that there is advanced mining.