Some Linux distros are already using non-linux kernels, e.g. GNU Debian/kFreeBSD, so Debian Linux is not Linux then.
Currently, Android is released using Linux kernel, ELF executable format, POSIX API's, and so on. There is no Android/kFreeBSD, nor Android/NT.
Android games can be launched on Linux using android libraries (not all, but some works pretty well, see: http://www.shashlik.io/showcases/ ).
Linux tools can be launched on Android systems (including X based tools, if X server is running).
For most of practical purposes, Android is Linux.