Hundreds is a puzzle video game where players touch circles to make them grow without overlapping. In the game's 100 levels, the player interacts with different types of circles to bring a counter to the number 100. The game was developed and published by Semi Secret Software in collaboration with Greg Wohlwend and was released for iOS on January 7, 2013, and on Android later that year.

It was originally built for Adobe Flash in 2010 as indie game artist Wohlwend's first self-developed game. The game idea came from staring at the ceiling, and Wohlwend applied a grayscale color palette from his first year in art school. When Flash game sites did not purchase the title, he open sourced the code. Eric Johnson of Semi Secret ported the game to iPad, which began a collaboration between Wohlwend and the company's Adam Saltsman, who became the primary puzzle designer.

The game received "generally favorable" reviews, according to video game review score aggregator Metacritic. It was an honorable mention in Best Mobile Game and Nuovo Award categories of the 2012 Independent Games Festival, their honorable mention in Excellence in Visual Art the next year, and an official selection at IndieCade 2012. Reviewers praised its minimalist design aesthetic and puzzle variety, and criticized its obtuse cryptography subgame. Ian Bogost wrote that the game functioned like a design object, a feat unique for the video game medium.

Players touch circles onscreen to make them grow in size. Numbers within the circles count upwards with the duration of the touch. If a growing circle overlaps another, the player must restart the puzzle. Levels are completed when the numbers within the circles total 100. There are 100 levels that progress in complexity from a simple circle with no nearby obstructions to the advanced mechanics, such as linked circles that need to be touched at once, buzzsaws that reset the numbers within the circles, and snowflakes that freeze other circles.

The game has no pause feature or motion controls, and there is no formal tutorial. Hidden between the puzzles are a few ciphers—incomprehensible text to be decoded through substitution cipher and other methods. The endless mode unlocks when the 100 puzzles are complete, and features a series of randomly generated levels.

Hundredswas developed by Semi Secret Software: Adam Saltsman of Canabalt, Greg Wohlwend of Puzzlejuice, composer Scott Morgan (also known as Loscil), and developer Eric Johnson.

I imagined growing a circle as large as possible without having them touch whilst growing. The victory/death case was so intrinsically linked I could play it in my head and feel how much patience it would take in certain cases.

Wohlwend originally built Hundreds as a Flash game. As an artist, he wanted to experiment with game programming following his release of Solipskier with programmer Mike Boxleiter. He developed the game from an idea he had while staring at a ceiling, where he imagined a circle growing without overlapping another when growing. He found this to be a good core game concept and based the game around "patience and persistence". The game's style inadvertently borrowed from his first year in art school, where Wohlwend composed in black, white, and red so as to focus on composition rather than color. The Flash version was released in 2010 and is available online at Newgrounds. The Flash version was much simpler in design, and added circles onscreen as the game progressed. This gameplay evolved into what became the iOS release.