Dr. Nano for the iPhone and iPod Touch
As a kid, I always had a special place in my heart for the various movies and theme park rides (Body Wars at Epcot) that involved being shrunk down, and placed inside the cardiovascular system. So I was excited by finding an iPhone game with that same basic premise, but it turns out, shrunken body fun might be best enjoyed only as a kid.
In Dr. Nano, you swim through arteries/veins, and pilot a robotic contraption to zap parasites, plaque, and other evil doers, while collecting red blood cells. As an adult, the gameplay becomes monotonous fairly quickly, but I could see a certain age group, maybe 8-10 really enjoying Dr. Nano.
What the kids (and their parents) probably won't enjoy is the current $3.99 selling price. This game would be solid at $.99, but when you're competing around the same price point as fully fleshed-out, kid's franchise games like SpongeBob, and Toy Story, this price just won't fly.
Take a look: