Pony Island is officially described as a "suspense puzzle game in disguise". At the centre is an action game called Pony Island. It is a simple 2D side-scrolling game where the player uses the left mouse button to make a pony jump to clear gates as it moves forward by itself. Similar to the concept of Frog Fractions however, that is only a starting point for a much broader experience. As the game breaks down, the player slowly delves deeper into the game that turns out to be an arcade machine devised by a sinister force. The game Pony Island is a recurring theme that returns in many different forms, with different protagonists, colours and enemies, but also improved abilities such as wings to float in the air and a laser to destroy creatures.
The player has to investigate the computer running the game, revealing secrets by manipulating items, text chatting with the creator of the game as well as an entity that wants to free the trapped souls, browsing documents and programs, logging into different accounts and so on. This is the adventure aspect of the game, which is largely linear, but requires the player to interact with the interface and the many errors and code in unusual ways to progress, often deliberately breaking game mechanics. There is also another dimension to the game, to find out who the protagonist is, playing the arcade cabinet. Optionally four hidden visions can be unlocked. There are 24 hidden arcade tickets in the game and collecting them all leads to a different ending.
Another important game element is the pseudohacking. Many moments in the game let the player break the rules devised by the creator by hacking directly into the game code. This is presented as a puzzle sequence with a series of instructions performed in a continuous loop. The player has to drag icons to manipulate the processes: duplicating them, guiding them in a certain direction, using a teleporter to skip or repeat certain instructions and so on, until a goal is met. These are puzzle sequences based on logic and no programming knowledge is required.
The game often deliberately breaks the fourth wall and attempts to confuse the player. It was originally created as a Game Jam entry for Ludum Dare 31 (theme: "Entire Game On One Screen") in 2014 and was then developed into a full game.