In the style of the sort of compilation release that a publisher like Sega, Atari, or Nacmo might release containing a bunch of older titles from its back-catalogue. With UFO 50 though the titles will all be new games from the creators of indie hits like Spelunky, Skorpulac, Time Barons, Madhouse, and Downwell. Numbering a whopping 50 in total! And, as a single package it looks awesome.
As per the FAQ about the upcoming anthology collection due for release in 2018, the developers note that "the games are slightly smaller than commercial 8-bit titles from the '80s, but rest assured that they are full games and not microgames or minigames! Completing the entire collection could easily take over a hundred hours" and "the story of UFO 50 is that the games were all created in the 80's by a fictional company that was obscure but ahead of its time".