It does get harder, yes. Some levels are hectic, and some levels are tricky. And there are some surprises along the way. It's a bit hard to capture the difficulty in a video since what's different is, well, invisible. And also I don't want to give away the solutions to the more interesting episodes (or ruin the surprise). To quote Osmos:

"Is there a demo of Osmos I can try first?

Yes, but don’t let it fool you. The game starts gently, but there are some truly difficult levels later on in the full game."

http://www.hemispheregames.com/osmos/

That said, your point is well taken. I'll think if I can improve the video somehow, or perhaps have an Osmos-like disclaimer around it.