Sega Enterprises released the game Zaxxon on various platforms, they also happened to release it on the old IBM-PC in 1984. I think it was best played with a joystick but as I don't happen to have one I am playing it with the keyboard. That is trying to play it with a keyboard. The ship needs repeated key-presses to move as there is quite bit of lag for it to move on its own.
Everything seems to be there, a nice isometric game that seems to be tougher than the arcade port even. A definite must have in a retro arcade PC gaming collection I say.

Check out how I did (poorly) in the video.

Centipede on the IBM PC programmed by R.J.Grafe in 1983. It's not the official port by Atarisoft but another release sporting quite an innovative control scheme. It actually features a simulation of the trackball found on the original arcade game. It uses the space bar for firing and the cursor keys to move around the little gun-turret. Pressing a directional key is similar to giving the trackball a swirl. Pressing multiple times in rapid succesion is like giving the trackball more momentum. A bit of an indirect control scheme but it really works well. With this control scheme in place this actually makes for an excellent port.

Take a look at the video and see how I fared.