Critics applauded the amount of variety, experimentation, and consistent quality that the collection provided, although some wished specific entries were expanded as their own separate releases.

The games vary in length and scope, with some being described as "shorter, arcade-style experiences", while others "have narratives and expansive worlds to explore", with one (Grimstone) estimated to take upwards of 60 hours to complete fully.

The idea to create a collection came from Yu's belief that these concepts for games, if expanded, would not do well as standalone releases in the current marketplace.

"[23] Three additional developers joined at various parts of development: Ojiro Fumoto, known for Downwell, who spent a half-year on the team and directed Seaside Drive; Paul Hubans, known for Madhouse, who was the lead director for Night Manor; and Tyriq Plummer, known for Catacomb Kids, who ended up co-directing several of the collection's largest games, an example being Valbrace.

[24] Every member of the team contributed design, writing, artwork, and programming to UFO 50, and worked on anothers' games, sometimes extensively.

[25] This meant that development times became inflated, and it became a requirement for the team to recode older parts of the game, with Yu describing some of the code as "prehistoric".

[5] Some games across the collection reuse sound, assets and code, the most notable example of this being the Campanella series which all make use of the same engine.

[31] UFO 50 received "universal acclaim" according to the review aggregator website Metacritic, with an average score of 91[32] making it the highest-rated PC exclusive of 2024.

Eurogamer's Christian Donlan extensively praised the experimentation and variation of games in the collection, calling it a "dazzling piece of creative audacity".

[38] 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".

[41] In contrast, PC Gamer's Kerry Brunskill remarked that they would have rather seen some games in the collection "stand on their own merits" as standalone releases, with others being "a little too retro for their own good".

[34] Games in UFO 50 that were singled out by multiple reviewers as being exceptional include Mortol,[34][35][39][45] Party House,[35][37][38][39] Rail Heist,[37][38][46] Night Manor,[37][38][40][48][49] and Mini & Max.