Actronics Twinvader III (1981, VFD, 4 C Batteries, Model# 3213)
Manual in PDF is available. (for the Tandy version: Cosmic 2000 Fire Away).

Made by Hanzawa (they made most of the Actronics games and a few for CGL). Also called just Twinvader, probably released under that name in another country. Also licensed to Tandy/Radio Shack as Cosmic 2000 Fire Away. Check out the Guts section to see the inside of this game.