Once you kill ten monsters in one level, you can move on to the next. The monsters in each level get stronger and harder to kill, but you also get more money for killing them. After every ten levels, you have to face a difficult boss who has to be killed in less than 30 seconds.
You can access the menu and upgrade your heroes at any time. You start off with one hero but can acquire more, which help you cause more damage. It's absolutely necessary to have multiple heroes to beat the monsters in the higher levels.
Clicker Heroes is a simple game (like many in this genre) and isn't especially original. The graphics aren't anything special ... and neither are the heroes.
Requires Android 3.0 or higher