Happy Wheels

According to Bonacci, a sequel, which he has been working on since at least 2013, is still in development as of December 2020.

Happy Wheels' tagline is "Choose your inadequately prepared racer, and ignore severe consequences in your desperate search for victory!" The actual mechanics of gameplay vary because of character choice and level design; the game includes characters such as a dad and his son riding a bike, a businessman on a Segway, a homeless man in a rocket-powered wheelchair, and Santa Claus in a flying elf-pulled sleigh. The goal of the game also differs depending on the level. In most levels, the goal is to reach a finish line or to collect tokens. Many levels feature alternate or nonexistent goals for the player. Reviewers have noted Happy Wheels' graphic violence. For instance, characters can be decapitated, shot, or crushed by various obstacles. Loss of limbs and profuse spurts of blood are also graphic elements. Players also have the choice to upload replays of their level attempts, which can then be viewed by other players. Happy Wheels features a level editor, which allows players to create custom levels of their own. It contains a plethora of tools and objects for level building. Users can upload their maps to a public server where they are accessible.

Indie game developer Jim Bonacci, the game's main programmer and artist, began work on the game in 2006. Bonacci has said that his inspiration for the game came from other ragdoll physics-based games in the browser games community, as his friend and former boss, Alec Cove, had made a Verlet physics engine for Adobe Flash. Per Bonacci, "I was messing around with it, and eventually created a guy in a wheelchair that would endlessly fall down a random hill. I thought it was funny and stupid, so I kept expanding on it. It was only meant to be a very small game, but eventually it became my main focus." The hyper-violent nature of the game was a reaction to Bonacci's frustration with how the consequences of certain actions were not treated realistically in other game titles. Bonacci stated that "it always bothered me when... you'd fall off your vehicle and harmlessly bounce around. In other cases, you would have the same canned animation over and over. I'm not sure if it was a lack of detail or concern on the part of the developer, but the consequences of your in-game actions were often improperly illustrated. For me, half of the fun of playing a game that imitates life (sort of), is making mistakes and seeing the end result." Bonacci also noted that, because gameplay would often involve the player dying repeatedly, he put a great deal of effort into making that part of the game enjoyable. The full version of Happy Wheels is only available on Bonacci's original website, totaljerkface.com. Bonacci's other game, Divine Intervention is also available there. Demo versions of Happy Wheels are licensed to other major gaming websites like CrazyGames. These demo versions only include a limited number of featured maps and playable characters. There are approximately 10 million user-generated levels. The total count of level plays is over 13 billion. Jason Schymick has helped Bonacci work on the game programming, although different people have contributed. "The others who helped are all amazing", says Bonacci. Alec Cove joined Fancy Force in 2013 and handles all server-side architecture and development. On September 30, 2014, Schymick announced that iOS and Android ports of the game have been in development. The iOS version was released as a free download through the App Store on August 20, 2015. For the Android version, Fancy Force began accepting beta test applications in October 2019. Following a beta testing phase, the finished version was released on January 25, 2020. On January 9, 2020, Bonacci posted on his website that a JavaScript port by Goodboy Digital was in development and the game would continue to function after Adobe Flash ended at the end of 2020. Eleven months later, on December 28, 2020, the JavaScript port was released, continuing the existence of the game after the end of Flash.

In November 2016, a 9-episode animated web series based on Happy Wheels titled Happy Wheels: The Series premiered on Verizon’s go90. Produced by Machinima, Inc. and Bunim/Murray Productions digital division BMP Digital, Happy Wheels: The Series is set in the title town, dubbed as "the most dangerous community on Earth" where "people are mangled everyday by traps, spikes, mines, cars, unsafe roads and hazards." Five concerned citizens form a safety awareness committee called D.E.A.T.H.S. to prevent any more casualties, but end up either killing more people directly or falling victim to the traps theirselves. The series has been removed aside from a few archives after the shutdown of go90 on July 31, 2018.