VVVVVV

Unlike most platforming games, in VVVVVV the player is unable to jump. Instead, the direction of gravity can be reversed when standing on a surface, causing Captain Viridian to fall either upwards or downwards. The player uses this mechanic to traverse the game's environment and avoid various hazards, including stationary spikes and moving enemies. Later areas introduce new mechanics such as moving floors or rooms which, upon touching one edge of the screen, cause the player character to appear on the other side.

VVVVVV contains eight main levels, including an intro level, four levels which can be accessed in a non-linear sequence, two intermission levels, and one final level, only seen outside Dimension VVVVVV (in a "polar dimension"). These are situated inside a large open world for the player to explore, spanning more than 400 individual rooms. Due to its high level of difficulty, the game world contains many checkpoints, to which the player's character is reset upon death.

The player controls Captain Viridian, who at the outset of VVVVVV must evacuate the spaceship along with the captain's crew when the ship becomes affected by "dimensional interference". The crew escapes through a teleporter on the ship; however, Captain Viridian is separated from the rest of the crew upon arrival. On returning to the ship, the Captain learns that the ship is trapped in an alternative dimension (referred to as "Dimension VVVVVV"), and that the ship's crew has been scattered throughout this dimension. The player's goal is to rescue the missing crew members and determine the cause of the dimensional interference.

The gravity-flipping mechanic of VVVVVV is based on an earlier game designed by Cavanagh titled Sine Wave Ninja, though this novel feature was first seen in the 1986 8-bit game Terminus. In an interview with Indiegames.com, Cavanagh said that he was interested in using this idea as a core concept of a game, something he felt other games which include a gravity-flipping mechanism had never done before.

Cavanagh first unveiled VVVVVV on his blog in June 2009. The game had been in development for two weeks, and Cavanagh estimated that the game would be finished in another two, "but hopefully not much longer." A follow-up post published in July 2009 included screenshots of the game and an explanation of the game's gravity-flipping mechanic. Cavanagh wrote that VVVVVV, unlike some of his previous work such as Judith and Pathways, would not be a "storytelling experiment", but rather "focused on the level design".

VVVVVV has been generally well received by critics, earning a score of 81/100 for the Windows version and 83/100 for the 3DS version on review aggregator website Metacritic. The game was noted for being the first important independent release of 2010; Kieron Gillen of Rock, Paper, Shotgun called it "the first great Indie game of the year", while Michael Rose, writing for IndieGames.com, noted that the release of VVVVVV followed a year which "some may argue...didn't really deliver an outstanding indie title which showed the mainstream that independent developers mean business." The level design of VVVVVV was lauded by critics: Rose considered the game to have no filler content, which he found to be "one of the game's strongest points". Michael McWhertor of gaming news blog Kotaku wrote that the game's areas contained "a surprising amount of variation throughout...ensuring that VVVVVV never feels like its designer failed to explore the gameplay possibilities."

A number of reviewers wrote of VVVVVV's high level of difficulty. McWhertor found that "the game's trial and error moments can seriously test one's patience." However, several critics noted that the game's challenge is made less frustrating due to its numerous checkpoints, as well as the player's ability to retry after dying as many times as needed. These additions made VVVVVV "not unforgiving", according to IGN staff writer Samuel Claiborn, while still being "old-school in its demands of player dedication".