ZZT

ZZT is a 1991 action-adventure puzzle video game and game creation system developed and published by Potomac Computer Systems for MS-DOS. It was later released as freeware in 1997. It is an early game allowing user-generated content using object-oriented programming. Players control a smiley face to battle various creatures and solve puzzles in different grid-based boards in a chosen world. It has four worlds where players explore different boards and interact with objects such as ammo, bombs, and scrolls to reach the end of the game. It includes an in-game editor, allowing players to develop worlds using the game's scripting language, ZZT-OOP.