[15] A separate Rumble mode, which incorporates unusual power-ups, such as the ability to freeze the ball in place or cause a single opponent to have difficulty controlling their car, was added on September 8, 2016.

It takes place in an arena without any goals and a field made of hexagonal tiles, and uses a ball that becomes increasingly electrified after successful strikes or passes.

After a 6 minutes, if a winner has not yet been decided by being the only remaining player with one or more lives, the match enters Sudden KO mode, where all actions are much more powerful and exiting a safe zone around the map removes a life.

They had toyed with several options such as race modes or mazes, but found that when they added a ball to the arena to be pushed by the vehicles, they had hit upon the right formula, which would become Battle-Cars.

[39] They eased up on some aspects to make it more approachable, such as by slowing the pace of the game and allowing players of all skill levels to reasonably compete against each other while promoting team-based gameplay.

[31] They also explored other changes such as making the game more gritty, akin to Monday Night Combat, developing several mini-games related to handling of the car, working on making the graphics give a sense of scale to the players to give the impression they were controlling full-sized vehicles rather than radio-controlled cars, and creating an open world structure where the player would drive between stadium and stadium to participate in matches.

[40] At the time of Battle-Cars, Psyonix could not afford a dedicated server network and were forced to rely on individual hosts, which could lead to poor performance with slow Internet connections.

[36] Though they had put in efforts to establish a free-to-play model, Psyonix decided instead to switch to a traditional sale method, and offer only cosmetic elements as downloadable content, assuring that no players would have any additional advantage beyond their own skill.

[38] The name Rocket League was selected in part to reduce the size of the game's title in order to appear fully in digital storefronts, and also served to be an easier to remember name as well as a more mature-sounding title than Battle-Cars, according to Hagewood;[31] speaking on Rocket League's development in March 2016, Davis opined that Supersonic Acrobatic Rocket-Powered Battle-Cars was "the worst game name of all time".

[47] Psyonix determined the required technical steps needed to enable cross-platform play and have tested it in closed environments, and were only waiting for the legalities of cross-connecting players between different networks before proceeding.

[42] In a July 2016 interview with IGN, Dunham stated they had done all the technical work and could enable cross-platform play between the Xbox One and PlayStation 4 versions "within a few hours" of Sony's approval.

Sony still opted not to participate in this; PlayStation global marketing head Jim Ryan said that while they are "open to conversations with any developer or publisher who wants to talk about it", their decision was "a commercial discussion between ourselves and other stakeholders".

[51] Dunham says that in contrast to Microsoft or Nintendo, who agreed to allow cross-platform play within a month and with the day of Psyonix' request, respectively, Sony has been asked on a nearly daily basis about this support and have yet to receive any definitive answer.

[53] By January 2019, Psyonix announced that Sony had granted the same for Rocket League, allowing cross-platform play between the PlayStation 4, Xbox One, Switch, and PC versions in February 2019.

[54][55] Psyonix planned to continue to support Rocket League with downloadable content (DLC), intending to keep all gameplay updates free and only charging for cosmetic items.

[60] In October 2016, a major update titled "Aquadome" launched, featuring a new arena placed under the sea, along with two new premium water-themed cars, and a new crate containing new items and seven new achievements.

[76] An update released in July 2017 introduced a new arena celebrating the one-year anniversary of the game, along with cosmetic items based on the American animated show Rick and Morty.

[83][84][85] For the 2019 Radical Summer event, Psyonix released two new car packs; the Ecto-1 from the Ghostbusters film franchise in June, and the KITT from the 1980s television series Knight Rider in July.

[93] New songs were added to the game with post-release updates, including "Chaos Run Theme" by Kevin Riepl, "Escape from LA (Instrumental)" by Abandoned Carnival and Ault, and a remix of Hollywood Principle's "Breathing Underwater" by Ether.

[38] They had originally planned to release the game around November 2014, but had missed this deadline to implement better matchmaking and servers, high frame rates, and removing the free-to-play elements.

[62] A retail version of Rocket League, in form of the game's Collector's Edition, was announced in February 2016, and was released in Europe on June 24, 2016, and in North America on July 5, 2016.

[115][116][117] Due to the Switch's lack of natural support for Unreal Engine 3, some compromises had to be made in the porting process, such as by reducing the graphical quality to 720p.

[118] Austin, Texas-based studio Panic Button assisted Psyonix with the Xbox One and Nintendo Switch ports,[119][120] and graphical updates to support the PlayStation 4 Pro.

[121][122] In April 2017, Psyonix announced that they had partnered with Tencent to bring a free-to-play version of Rocket League to the Chinese gaming market, with users able to purchase cosmetic items through microtransactions.

Psyonix has had a long-standing relationship with the studio (its original North Carolina headquarters were only 12 miles (19 km) away from those of Epic), having worked with it on development tools for the Unreal Engine.

RLCS Season X would bring the addition of a new competitive format which featured 3 separate regional splits, each one having their own international Majors, followed by the season-ending World Championship.

[170] In a review of Rocket League's beta preview, Ozzie Mejia of Shacknews praised Psyonix's approach to updating Battle-Cars using the PlayStation 4's hardware, describing the graphics as "brilliantly detailed" and "crisp", and citing its consistent frame rates throughout.

[172] Neil Bolt of PlayStation Universe shared a similar view, writing that the physics "causes frustration in 4v4 bouts where everyone ends up huddling under the slow-descending ball for long periods.

[170] In complimenting the game's points system, Elliott recounted, "the most valuable players I encountered were workmanlike wingers who selflessly chugged along the flanks, crossing the ball for greedy goalhunters like me.

"[170] In a retrospective review written two years after its release, Alec Meer of Rock Paper Shotgun shared similar feelings about the player experience in Rocket League.