Shadow Man deals with a world of voodoo and the land of the dead. They call this land "Deadside". As Shadow Man you are protector of Deadside. You are sent to collect the dark souls and stop Legion and Jack the Ripper (plus their minions) from collecting them. This is a game of dark subject matter, which is a nice change of pace for a game on a Nintendo platform.
I enjoyed my time in Deadside. The world is well built and the mechanics are fairly solid. There is some good platforming here and the dual wield system for the weapons was a nice touch. As for weapons, you have both real world guns and voodoo weapons. Most of the weapons also have some use in solving puzzles, which makes them more useful than for just killing the bad guys.
All that being said, I did have some problems. The N64 version had some bugs. I had the game freeze once, monsters would disappear through walls and walk through doors, and at one point the camera pointed at the ground for a transition scene. The camera got in the way at points too. There was no real easy way to control it on the N64, which in turn made some of the platforming elements difficult. Also the strafe targeting did not always work so well. It often would lose its lock and either target nothing or switch to another enemy.
I also felt that this game needs a map. It is a very drab world, which is appropriate given that Deadside is essentially Hell. This drab world makes it easy to get lost. A lot of it looks the same, and sometime the textures would blend together and you would not notice a path. There is also a lot of backtracking, so a map would make things a little bit easier and more enjoyable.
You can currently get this game on Steam and GOG for a few dollars. So if you want to check it out, it is still available on the PC and Mac, and I would say worth the few dollars. You could also dig up used copies for the PlayStation and Dreamcast.