Bot Arena 3 is a fun way to waste time. The aim of the game is to build a robot that fights other robots. You start by building a small bot with some simple weapons and end up managing a team, making sure you meet the wait requirement and wondering what will be the best combo to beat the next level. It is difficult, but it is really a lot of fun.
Something to do, when if you like to click and watch. The instructions is a bit long and tedious but in general is an excellent game.