Well, I have some ideas about the game. It will be inspired in the novel "a fantastic journey".

You will drive a miniaturized ship through someone's body and will have to somehow kill bacterias visuses and whatever.

Game controls will be based on colour tracking with a webcam, accelerometer (android) or just mouse (if other things are missing).

http://youtu.be/dlaJ8NHRFekls

Well, still needs a lot of work but it works. 

Well, I had no time for documentation, help menu, artwork and many other things.

By the way, unzip the file journey.zip and execute main.py.

For playing you'll need a compatible webcam and something with 2 areas of a bright colour that will be your input device. (see video at http://www.youtube.com/watch?v=dlaJ8NHRFek)
In configuration you can left-click for choosing the color to be tracked and use wheel for adjusting threshold. Once you see the tracking is well calibrated, right-click.

If there's no compatible webcam, mouse input will be used.

The gameplay is simple, you drive a miniaturized ship and make viruses to crash against each others while avoid to touch them.

Enjoy!

Thank you all for the comments. 
Hope next time will have more time to give you a real game.
Consider this as a proof of concept.