Board Thread:Questions and Answers/@comment-25523075-20160401140435

The Rubber Block page says:

"In Bloons 1 series, the darts can hit the rubber blocks for up to 25 times before disappearing. In Bloons 2 series, the darts can hit the rubber blocks for up to 15 times."

'''I tried hitting the rubber block in Bloons 2 15 times, but it didn't disappear. Why didn't it disappear?''' 