Zaxxon was one of those groundbreaking games back in the day, the first game to feature an isometric 3D view. In addition the playing field had a sense of depth where your ship could travel along the z-axis of the playing field. It was also one of the first (if not the first) games to feature a boss, the robot Zaxxon himself.
The colecovision version keeps the isometric view but at a large sacrifice of gameplay. First thing you notice are the accurate graphics that look better than any other home version of the time. Second thing you notice is that the game moves at a snail's pace. Third thing you notice is that the game is in fact, crap.
Graphically it looks good when it stands still. Crappy scrolling immediately destroys this illusion. You can still travel up and down the Z-axis to nail different targets. There are still rockets that shoot up from the ground, gun turrents, walls, etc, but since your ship feels like a baby wilderbeast swimming through the LaBrea tarpits you tend to crash into stuff before you get a chance to blast it. I find it's much easier just to fly to the maximum altitude and just dodge everything, which defeats the whole purpose of the game. Add to the fact that if you stay in the air too long not only do you run out of fuel but a guided missile shoots you down.... ugh. Once again the Coleco monkey team must have play tested this thing.
This version is vastly superior to it's contemporaries (for instance, the 2600 version that doesn't even look like the same game) but modern gamers with acess to MAME need not look at this dinosaur.