Time for another confession... I enjoy killing bloons!
Bloons TD 5 is a tower defense game, meaning you set towers along a course to defend whatever needs to be defended. In BTD5, you want to keep the bloons from getting to the end of the course.
You do this with different monkey towers, each with different abilities. There's the simple, dart-throwing monkey, the ninja monkey and many others to choose from. Each with different upgrades.
I'm at level 55 now. I've beaten most of the levels on easy and medium...except the advanced and extreme levels. I'll go for hard later. It's a way to let the brain relax for a few minutes and de-stress.
You can give it a try here or on Kongregate where I play. Just don't get addicted. :-)