In the "golden age of gaming" in the late 1970's and early 1980's, there was a great rivalry between the Atari 2600 (launched in 1977) and Mattel Electronics' Intellivision (launched in 1979), which came to be known as the first great console war. It was highlighted by a series of competing, high-profile print and television ads from the two companies. Many of Atari's biggest hits were their arcade adaptions (often titles ported from their own coin-operated division), such as the home version of Asteroids. So of course, these games were showcased in their ads, while Mattel's Intellivision ads famously featured actor and sports journalist George Plimpton touting the advanced (for the time) 16-bit graphical capabilities of their system. And these graphics spotlighted the difference between early Atari sports cartridges like baseball and football, with the more polished look of competing Intellivision titles.
One would think that a console with superior graphics would have been more successful than one with more limited capabilities such as the Atari 2600. However, with the success of their arcade ports, such as their first "killer app" Space Invaders, along with unique home titles like Yars' Revenge, the 2600 was a huge commercial success. So, in 1982 Mattel Electronics joined a long list of companies making games for the Atari 2600 by introducing their M-Netwok line, which included many ports of popular Intellivision titles. And although the "Intelligent Television" system (these words combine to make up Intellivision) was known for excellent sports games, they did have other notable titles as well. One of them was a top-down maze shooter designed by Steve Montero called Night Stalker, which was ported to the Atari 2600 in 1982 as Dark Cavern.
In Dark Cavern your man enters the "underground cavern", which is a fixed maze configuration, in a quest to destroy as many enemies as possible in order to earn as many points as possible. You have a limited amount of ammunition which can be replenished along the way by running over gun symbols that flash on screen for a short time, while the threats encountered are spiders, blobs and robots. A "bite" from a spider stuns your man, leaving him totally vulnerable for several seconds, while making contact with a blob robs you of ammunition (more is lost the longer the contact lasts). But the robots are the enemies that can immediately cost you a life if they shoot your man, while at the same time being worth all the points when they are destroyed. Additionally, the speed at which you can destroy them is relevant here, because if they are taken out fast enough (before new ones enter the maze) point values increase. And this must be done with the limitation of having only one bullet on screen at a time, as there is no rapid-fire in the game.