NIGHTSHADE is a game originally for the NES (Nintendo Entertainment System). Now released on STEAM. YAY!
As for, "When It Takes Place?" I'm honestly not sure. The story/game style is of the Noire category.
By which I mean, Detectives, gangsters and the like. HOWEVER! Some of the cars, the crime computer in your Hideout and other things place this game solely in the modern era. To rationalize,
I would say that this game most likely takes place in the future, as seen in seventies style comics.
Advanced technology, secret hideouts, yet still with town criers and gangsters. A mix of Sci-Fy meets roaring 20's style events. Honestly, I could see this whole game as a vintage Marvel or Topcow comic
story that ran for a few years. As for "Who You Are?" I will simply state what the original Manual for the game said. That you are a child raised on the news of a rogue hero named Vortex. One day, Vortex disappeared. The city continuing to get worse, you decided to become a masked vigilante hero yourself and pick up where he left off, trying to make the city a better place.

UNFORTUNATELY, you are caught almost immediately. Having to first start by escaping a bomb,
your journey begins anew. Can you figure out what happened to Vortex? Can you save the city? ONLY TIME, WILL TELL. GOOD LUCK!

So, best as I can figure, the controls are as follows...

Up, Down, Left & Right arrow keys control your walking directions.

Space brings up your menu.

X, accepts.

Esc brings up the options menu. Mostly only used for sound or quitting the game. Though it WILL, tell you your % of game completion. This is important as you can use it to help you gauge what's important or not.

COMBAT CONTROLS

Z Punches.

X Jumps

??TBD?? fires the Staff of Ra.

HERE WE GO ! The game starts off with NIGHTSHADE tied to a chair. After Sutekh monologues about how useless and pathetic you are he disappears. IMMEDIATELY move down, left, and up, behind the wall to escape the bomb blast. THIS IS TIMED !

GOOD! Now walk over to the candle, bring up your menu and use the "Take" key to take the candle. This will be useful later. Then exit stage right.

FIVE TIMES.

You can only escape death five times. So don't waste your life!!!

1. The conveyor Belt.