UFO 50

UFO 50 is presented as a compilation of games similar to Cassette 50 and Action 52, developed by the fictional company UFO Soft for the fictional LX-I, LX-II, and LX-III series of video game consoles between 1982 and 1989. Half of the games feature a two-player mode, either versus or co-op. The main 50 games are playable from the start, with the hidden 51st game, Miasma Tower, accessible via inputting commands in the in-game terminal.

The order in which the games are presented is intended to show the history of UFO Soft's development slate, with some games having sequels, and others featuring cameos from previously released games. Each game also features short development notes informing their fictional creation.

Within the game are references to the metagame and a secret storyline about the fictional game development studio UFOSoft. The hidden 51st game Miasma Tower was a game secretly developed by fictional developer Gregory Milk, which details the state of UFO Soft circa July 1989. In-universe, the UFO 50 collection is stated to be developed by Milk and never released officially, with the files found in an abandoned warehouse by the Mossmouth developers, as shown in the faux-cracktro of the game.

Derek Yu and Jon Perry had previously developed a number of freeware games together using Klik & Play under the name Blackeye Software, with notable titles being Trigger Happy, Diabolika (remade in UFO 50 as Devilition) and Eternal Daughter. In 2016, the two decided to work together again on a project, making smaller scale prototypes for ideas. These prototypes eventually spiraled into the concept for UFO 50: a large collection of small games. The idea to create a collection came from Yu's belief that these concepts for games, if expanded, would not perform well enough as standalone releases in the current marketplace.

The first game in the collection to start development was Attactics, which was fully developed by Yu and Perry alone as a re-introduction into working together. Soon after, Eirik Suhrke was invited to join as both composer and designer, and the three started to brainstorm games on a private forum, with a majority of these concepts making their way into the final game. The number of games advertised in the collection (50) was chosen by Yu because "it was the first number I could think of that was completely undeniable... that would advertise itself with its own existence."

UFO 50 received "universal acclaim" according to the review aggregator website Metacritic, with an average score of 91 making it the highest-rated PC exclusive of 2024. 100% of critics recommended the game according to OpenCritic. Many reviewers chose not to give traditional scores due to its nature of being a collection of 50 individual games. DigitalTrends alternatively chose to score all 50 individually in their review.

Most reviewers lauded UFO 50's variety, value, and experimentation. Eurogamer's Christian Donlan extensively praised the experimentation and variation of games in the collection, calling it a "dazzling piece of creative audacity". Simon Parkin of The Guardian described the collection as "a preposterously ambitious undertaking". Edge wrote that when one game "holds your undivided attention for an extended span, it must be something special indeed, and of those, UFO 50 has more than its fair share".