A fan game given coverage on sites like Destructoid and Gamezone has turned out to be infected with a keylogger. If you saw the coverage, got excited and instantly downloaded the demo (which would have been pretty understandable, it looked great), you'd be best to delete the game as quickly as possible to avoid any unwanted information slips.
More than that, you'll need to jump into regedit and delete HKEY_CURRENT_USER/Software/NakaSMK to be certain that the keylogger has disappeared. There are plenty of tutorials for that on the internet.
The best thing about this whole thing? The message that still remains on the game's home page:
"YOU MAY EXPERIENCE A WARNING MESSAGE FROM YOUR ANTIVIRUS SOFTWARE INDICATING A TROJAN IS PRESENT IN OUR ZIP FILE. YOU CAN BE REST ASSURED IF YOU ARE DOWNLOADING IT FROM ANY OF THE LINKS ABOVE THAT THE FILE IS SAFE."
