Hi myk45,
I'm not sure which games you're referring to, but they almost certainly used skinned meshes.
As you probably know, sprites need a new image for each frame of animation and every possible angle, this requiring a ton of memory and limiting your flexibility.
Skinning on a phone isn't as expensive as you think since it can be done in the GPU with OpenGL ES 2.0 vertex shaders. There's a
skinning training course in the Imagination Technologies SDK. This should work on mobile devices and PC emulation.
Good luck!