The Android manifest has the
< compatible-screens > node that you can use you limit which display sizes and pixel densities are supported. It's worth noting that I believe this node is used primarily by the app store rather than the device itself, so I don't think it will prevent you installing it on a smaller device if you force it; it will only tell the store (e.g. Google Play) not to install it on incompatible devices. It's also worth noting that the screen sizes are a little vague and manufacturer defined, so you can never be quite sure what it will cover. For Nexus of Power, which is a tablet only game, I used the following.
<compatible-screens>
<!-- all large size screens -->
<screen android:screenSize="large" android:screenDensity="ldpi" />
<screen android:screenSize="large" android:screenDensity="mdpi" />
<screen android:screenSize="large" android:screenDensity="hdpi" />
<screen android:screenSize="large" android:screenDensity="xhdpi" />
<!-- all extra-large size screens -->
<screen android:screenSize="xlarge" android:screenDensity="ldpi" />
<screen android:screenSize="xlarge" android:screenDensity="mdpi" />
<screen android:screenSize="xlarge" android:screenDensity="hdpi" />
<screen android:screenSize="xlarge" android:screenDensity="xhdpi" />
</compatible-screens>
Hope that helps.
