If you know Flash, you can make games for that slick little U10 “The iRiver U10 is a new portable media player from Reigncom Ltd. whose entire user interface is implemented in Flash Lite 1.1. This means the player itself is embedded in the operating system. The device has the ability to play back Flash SWF files that you transfer to the device using the included USB cable. The device’s unique form factor and UI make it particularly well suited for simple Flash games. The device has a four-way navigational control built into the display screen. To press Up, Down, Left, or Right, you actually squeeze the edge of the screen, which produces a slight tactile click and sends a keyPress event to the Flash Lite player.” Link.
HOW TO – Creating a Game for the iRiver U10