It's a sorry tale that when I see the National Science Foundation's logo, "NSF", my immediate reaction is, "Not Safe For what?!" I'm more disgusted with me than you could ever be. The letters come up via a game created as an educational tool called Immune Attack. It's a Fantastic Voyage-style (oh heck, I'm young enough to want to call it "an Inner Space-style) exploration game as you fly about inside the human body, interacting with things on a cellular level.
It's a shame it's been made with 300 year old tech - this could have looked all kinds of incredible if built with a more recent engine - but its purposes aren't to dazzle my idiot eyes, but rather learn things about biology.
It's free, the rather sizeable download available from the creators, the Federation of American Scientists. You can also make a donation to them should you feel so moved. They describe the aim of the game thus:
"You must navigate a nanobot through a 3D environment of blood vessels and connective tissue in an attempt to save an ailing patient by retraining her non-functional immune cells. Along the way, you will learn about the biological processes that enable macrophages and neutrophils – white blood cells – to detect and fight infections."
There's a trailer here too, but I'm a little concerned by their use of the word "alien". Unless this game was made by a Federation of American Scientists from another planet that also happens to have an America. I'm pretty sure that's what it is.