FreeIntv
A Libretro Intellivision Emulator
...The download here includes a pre-compiled binary for the Windows 10 (x64) and Raspberry Pi 3. Instructions for use with a typical Retropie installation on Raspberry Pi are also included.
A unique UI allows Intellivision games to be fully played even with a simple SNES style controller.
With a more complicated, playstation style, controller, the left analog stick will also allow for the full 16-directional movement, just like the original control disc.
You can follow development here:
https://github.com/libretro/FreeIntv
2018-02-13 Border collision bug fix
2018-02-12 Numerous fixes for various issues
2018-01-21 Update includes corrected installation instructions for RetroPie on a Raspberry Pi 3, a proper Makefile, and various small corrections.