N64oid won't work because CPU for the Samsung GT S5660 is based on the ARM6 archetecture (Yongzh limited his emulator to ARM7 only, so that he could use NEON math and optimizations that are only available for ARM7 devices). I am working on an open-source alternative N64 Emulator, which is currently in the first alpha testing stages on my website (
http://www.paulscode.com), and my emulator is designed to be compatible back to ARM5 (currently limited to devices with GLES2 until I write a GLES1 video plug-in.. I couldn't find on google if the Galexy GEO is GLES2 or GLES1). There is currently a graphics problem with Qualcomm chipsets (which your device has), but hopefuly I will have that solved soon. If you want to help out with the testing, stop by my website - regularly updated links to the current build will be posted there, along with known problems and other information.