3D Labyrinth is a first-person maze game by Jeff Minter of Llamasoft. It was published for the VIC-20 in 1982 and features very basic graphics, showing your view as a series of perspective-based drawings that change with every step you take.
The aim of the game is to escape from a series of randomly-generated mazes by finding the exit before the time limit expires. You can move forwards and backwards, and also turn left and right to move around the maze. It doesn’t seem possible to do anything else, though. There don’t seem to be any monsters, and there’s no way you can attack or do anything other than move.
It is possible to bring up a map of the maze temporarily, by pressing the ‘?’ key, but this costs you time. Time, I’m guessing, that is deducted from your total every time you look at it. Since there’s no on-screen indicator that shows the remaining time that renders the whole mechanic pointless, other than for completion times at the end.
The refresh rate of the screen movement is slow, so each step takes at least two or three seconds to update, and the perspective of the side passages seems a little off to me, so the feeling of movement through the maze is weird. The viewpoint, and the way the maze is drawn and generated, reminds me of the classic TRS-80/Dragon 32 game Phantom Slayer.
Minter was obviously playing with techniques that were not yet proven (the first-person viewpoint and tile-based movement were not really as accepted until Dungeon Master in 1987), and I don’t think Jeff had the patience to turn 3D Labyrinth into a fully-fledged RPG, so a simple maze/escape game it remained.