Ladder is a barrel-jumping game (like Donkey Kong) written for the CP/M operating system and made to be operated on the early Kaypro line of luggable computers.
Since the screens on these computers only accept text characters and not rendered graphics, the game uses letters, numbers, and symbols lined up to create walls and platforms, pits/traps, characters, trampolines and goals.
The floors in Ladder are made of equal signs and the ladders themselves are made of capital "H"s stacked on top of each other. The "lad" controlled by the player starts out as the letter "P" and barrels ("der rocks") are represented by "o"s.
The catchphrase of the game reminded the acolyte player that there are more ways than one to skin a cat. This referred to the fact that the minimized traverse of almost all levels could be enhanced by inventive utilisation of the game features, and the highest levels absolutely required it. These could entail (at the apex of the game) for instance jumping on a trampoline at precisely the right speed and point of impact to fall into one of the pit/traps, at the right timing that there would be no barrels passing for a sufficient interval.
Source: Wikipedia, "Ladder (Video Game)," available under the CC-BY-SA License.