The Pip-Boy 3000 Mark IV features minigames, which can be accessed if the Sole Survivor has found old tapes of these games. All games have a weight of zero and are worth 300 caps. They are also all retro games, to match the theme of Fallout 4, and are based on real-life video games published between 1978 and 1985.
The minigames are:
Atomic Command, a game where the character controls a stationary anti-missile weapon, shooting at missiles and planes before they hit the eight American landmarks at the bottom of the screen. Based on Missile Command (1980).
Grognak & the Ruby Ruins, a text-based role-playing game. You play as Grognak the Barbarian, seen in the comics throughout the Fallout games. You start an adventure, choosing your party, making decisions, and fighting through with many options. Based on The Bard's Tale (1985) and its assorted spin-off games.
Pipfall, a side-scrolling action-adventure game. You play as Vault Boy as he goes through the wasteland, all the while avoiding gas clouds, radioactive waste, creatures, and more. The player must collect 5 bobbleheads within 300 seconds, without losing their 10 health. Based on Pitfall! (1982).
Red Menace, a game where the character has to dodge the antagonist's barrels. You play as Vault Boy as he climbs ladders, run along platforms, avoids barrels and missiles, as you run up and save the woman from the Red Menace, and engage in several different stages. Based on Donkey Kong (1981).
Zeta Invaders, a game where the character has to shoot space invaders. You play as a cannon that can move left or right, shooting down waves of aliens and UFOs, and hiding behind 4 barns. The goal is to kill the enemies, increase your score, without losing your 3 health. Based on Space Invaders (1978).
Automatron, a game where the character has to shoot various robots and enemies. Running into one of these things will kill you. You can move freely, and to get to the next round you must kill all the enemies. Based on Robotron: 2084 (1982).