Have you ever been sitting in class wondering what to do with your spare time, perhaps you get all your work done or its friday and the teacher gives you permission to play games on the computer. (we all wish that could happen everyday right?) Anyways, as you know most of the games at school are blocked by filters or other proxies, making it so you cant access any of the games on a particular game site.
I would recommend personally to try something a little different, when I was sitting in class for long hours I would search for game sites that are not blocked, a game i would often play was called Bloons Tower Defense 3.
Start out by choosing which track you would like to use, then it asks for you to choose the difficulty. I would consider going with Easy to start out with. If its too easy for you then End game and choose a harder difficulty. Start out by placing objects (such as a dart monkey) on the designated areas and click Start Round. Be careful and dont let the bloons get ahead of you or your tower is going down and you fail!
In review i would say that this game is a fun and challenging game. Each round the bloons get harder to pop. Make sure you keep on buying upgrades. I found this game on freegameshacked.com. Stop by and check out this game and lots more. So head on over there now!