To make a gun game without a gun is like to have a Grateful Dead concert without the drugs, or have the Super Bowl without the football. Operation Wolf, taken from the arcade classic, represents exactly why you shouldn't make a gun game, without a gun!
Through the four levels of unexciting action, Operation Wolf doesn't scrimp when it comes to things to shoot. The problem is, none of the backgrounds, or really even foregrounds, are interactive. That is, you cannot shoot the houses, you cannot shoot the trees, and so on so forth. Even Cabal years earlier allowed you to interact with the backgrounds.
The control is stiff, also. With only two buttons you cannot get your pointer (that represents a gun) in quite the right spot when you want to. So often you get hit because you can't get to the right spot on the screen. And it feels like it cheats, too. Too often I know I shot them before they shot, but guess who get's hit.
Regardless, the game is fun for a while, and is worth taking a look at ... only in the arcade, though.