If you like clickers and games where you can combine things, Human Evolution is a good option to pass the time. In this adventure you've got to play God and create all kinds of creatures from the most basic elements.
In Human Evolution you've got to pop bubbles that appear and release a small DNA sample that serves to start developing your species. In this fun adventure you can experience and discover the entire evolution of different species up to the post-human, watching and learning from the evolution of the planet you live in.
To evolve your creatures you'll need two matching ones; click on them and drag them to the same position, one on top of another, to make them evolve. As you discover new creatures it'll take longer to find more new species, but it'll be worth the wait. Plus every species onscreen provides you with money you can invest and earn even more.
Human Evolution ends when you manage to discover the robots, although if you want to see how other beings besides humans evolve, you can delve into that new adventure and discover what, for example, giraffes looked like.