Gryzor might very well sound like the noise you make when you're trying to go to the toilet (or is that just me?), but it is in truth a rather large multipart (and multiload) scrolling kill-'em-up. It's a coin-up conversion as well, and despite the fact that it's an ex- YS Megagame from way back in 1989, and that (at first appearance) the graphics look rather shoddy, it still plays surprisingly well and is rather addictive. There's some stupid plot to do with aliens invading Earth again, but what you really want to know is what the game itself is all about. Well, whilst interacting with the scenery (such as choosing to run along the ground or wade through the water) you run along, kill people, shoot gun turrets and upgrade your gun to bigger and better things. At least, you do on the first level (and a few other ones later on), as Level 2 is completely different. Here, you have to negotiate your way through a 3D maze, which is done by standing at the bottom of each corridor, blasting aliens at the top, avoiding nasty zaps of electricity and turning either left or right. It may sound like a bit of a 'sub level', but it's a lot trickier (and more fun) than it may first appear.
Level 3 is more blasting as you climb up this cliff-face, avoiding falling boulders as you go. and Level 4 is a strange sort of firing range type level. Apparently, after this the levels sort of 'repeat' themselves, but are all changed for added excitement.
The only problem is that there've been stacks of this type of game before (they always seem to work well on the Speccy), and the ones that appeared after Gryzor did have proved far better. But since none of these better ones have been released on budget yet then I'm afraid you're stuck with this one. Don't worry - it's still pretty good, just ever-so-slightly dated.