The resolution of the screen on a given mobile device has a huge impact on how developers build apps and programs to run on the device. Most Android devices support 480 x 320 making apps compatible without much screen resolution issues.
With the launch of the new and cheap HTC Tattoo HTC has tossed a new resolution screen into the device that could hamper support for Android according to CNET Asia. The Tattoo has a resolution of 320 x 240, significantly lower than most other Android devices.
The problem is that with many games that use a customized UI, the smaller resolution could create an issue. That could mean that developers have to write the app to support more than one resolution, which might increase the time and expense needed to develop games. Development that is more expensive could mean apps that are more expensive. That could also mean that Android devices with lower resolution screens simply lack supported apps to choose from.