Classic Game Creations, is one of the best places to find homebrew Vectrex games on the web. In 1996 he released All Good Things, a cartridge with four of his homebrew games on it. I'll review each of the games individually, but I wanted you to know about John, what a champ he is, and what a great resource his site is.
Rockaroids is the first game on All Good Things and it brings a much needed Asteroids port to the Vectrex. The Vectrex was built to play games like Asteroids, so it's interesting that it took 13 years and a dedicated fan to make it happen. Anyway, Rockaroids plays exactly like the original Asteroids. You rotate your ship with two of the buttons, fire with another, and activate the thrusters with another. I would have preferred rotating the ship with the joystick, but the buttons work fine. One thing I noticed about Rockaroids right away is that the asteroids seem to be moving much more quickly than normal. It's like you're starting the game on the higher levels, which is nice if you're an accomplished Asteroids player. All in all, this is a very faithful and much appreciated port of Asteroids for the Vectrex. I would have done a couple things differently, but nothing major.