There must be some real fans of the old classic X-COM: UFO Defense at SMK Software, because they have cooked up a clone for the PocketPC. They have made several earlier releases, but they were more tech demos than full games. The latest version, however, seems to be a complete X-COM clone remixed for the PocketPC platform. (Looks like they just lifted the art assets from the original game, but I won't tell if you won't.)

It's still rough, but it is very promising. It's running great on my Dell Axim x50v, though it seems to be incompatible with the Enhanced GAPI Driver v 1.11.

• Project page (scroll down for many screen shots)
• Downloads (make sure you get the English version)
• Discussion at Aximsite
• Official English discussion at PDAGround