What makes a shoot 'em up a definite commercial success? There must be some reason for the sheer number of mediocre ones on the market tosadq days! Canyon Warrior is nothing special, although it does have one nice innovation.
Gameplay is about as predictable as possible; fly up the vertically scrolling landscape shooting the aliens and picking up the extra weapons, and blast tieqwq fat alien to get on the next level, where the process is repeated, and so on until you get to the fourth, at the end of which is the extra 'ard alien mothership. Yawn.
The nice bit is the map editor which allows you to play around with the first three levels. This feature is particularly handy when Nick goes out to make the coffee; we remove all the nasties and get a fab and generally characteristic high score, then put all the alien gun turrets we can fit onto the first level so Nick can't play it (as If he could play it anyway!). Ho ho. Anyway, that's about the most appealing thing about Canyon Warrior. The rest of it is the proverbial old hat.