Block

Blocks are obstacles in the Bloons series. They are generally annoying because they can impede your way but blocks like rubber blocks can be rather useful for aiming at tricky areas sometimes.

Ceramic Block

 * Light brown
 * Darts stop upon contact
 * 2 hits to break

Tile Block

 * Very light brown
 * Darts stop upon contact
 * 1 hit to break

Rubber Block

 * Impossible to break unless if a player is using a Super Monkey (skipping a level)
 * Dart bounces off

Perished Rubber Block

 * 1 hit to disintegrate
 * Dart bounces off

Metal Block
Note that you still may hear the metallic sound when using a Super Monkey, if it hits the block indirectly.
 * Impossible to break unless if a player is using a Super Monkey (skipping a level)
 * Darts cannot penetrate it
 * Metallic sound