I havn't looked at the world above since i was too lazy

, and I'm still new and only been programming for about 1-2 monthes so there maybe better answers but... but how about make it the object have 10 health, and when you click them, they lose 1 health, and decrement it by 1 when you click on it, so its takes 10 clicks for it to die. Or if you would like it to be at 100 health and lose say 10 health per click, make it something like this (this isn't the exact code, this is just off memory):
When mouse clicked on "object"
Set "health" value to ((health) - 10)