Well if it's like the psp there are certain hardware specific functions for things like memory management that need to be exploited for performance.
"The NDK allows you to
implement parts of your applications using native-code languages such as C and C++"
"
The NDK will not benefit most applications. As a developer, you will need to balance its benefits against its drawbacks; notably, using native code does not result in an automatic performance increase, but does always increase application complexity"
"Please note that
the NDK does not enable you to develop native-only applications. Android's primary runtime remains the Dalvik virtual machine."
http://developer.android.com/sdk/ndk/index.htmlYou're pretty much stuck with java.
However it does use OpenGL ES like a lot of other products, maybe a port of SFML for OpenGL ES would be a feasible starting point (once Laurent is happy with the OpenGL version)?