Spiral Knights

Spiral Knights is a massively multiplayer online game created by Three Rings Design and now owned by Grey Havens. The free-to-play, Java-based game was released in 2011 and is still updated occasionally.
In the game, the player controls a knight of the Spiral order, which has crash-landed on the mysterious planet Cradle. Knights cooperatively battle monsters throughout the Clockworks, the dungeon that fills the planet's interior. They also battle each other in an optional player-versus-player mode.
"Spiral Knights" reached one million accounts in its first three months and three million accounts in its first thirteen months. The game won Best Online Game Design, and was nominated for three other awards, in the 2011 Game Developers Choice Online Awards.
Gameplay.
The Spiral Knights are a spacefaring army from the planet Isora. Their ship, the "Skylark", has crashed on the planet Cradle. The interior of the planet is filled with a mechanized, continually reconfiguring dungeon called the Clockworks. Operating out of the town of Haven on the planet's surface, the knights descend into the Clockworks, with the goal of understanding the mysterious energy source at the planet's core. They hope to exploit this energy source to resurrect and re-launch the "Skylark".
In its gameplay, "Spiral Knights" is a top-down, third-person, real-time action-adventure game, comparable to "". The player controls a single knight, and may play solo or with other players. When exploring the Clockworks, knights cooperate to defeat crowds of enemies of various types, while dodging traps and solving simple puzzles. There are four main bosses, each with an alternate "Shadow Lair" variant, and numerous mini-bosses. In addition to this player-versus-enemy mode, there are two optional player-versus-player modes: one that is similar to Clockworks play, and a "Bomberman"-like mini-game that differs substantially from the rest of the game.
When they are not battling enemies or each other, knights train, shop, trade, and chat in Haven. Character progress comes not through the improvement of personal statistics, but rather through upgrades to equipment. Weapons include swords, handguns, and bombs offering various play styles and characteristics.
The game's visual style has been called "adorable" and "cutesy". The art work draws on many traditions and cultures beyond medieval European knights and outer space science fiction — for example, cowboys, wizards, ninjas, and chefs.
"Spiral Knights" is massively multiplayer, although each player interacts with a small subset of other online players at any given time. Clockworks parties are limited to four knights and player-versus-player contests are limited to six-versus-six. Instances (copies) of Haven typically have tens of knights present. Guilds are limited to 100 members by default, and friend lists are capped at 250.
The entire game is free-to-play. There is no in-game advertising. Players can spend real-world money to purchase an in-game commodity called energy. Energy can be exchanged for other commodities and currency, to accelerate a knight's development. Real money can also buy certain costumes and promotional items.
History.
"Spiral Knights" has been in development since around 2007. The game was released to advance testers on November 12, 2009 and to the general public on April 4, 2011. The game was released through the Steam software distribution system on June 14, 2011. It was also made available through gaming web sites such as Kongregate and Armor Games.
Critical response to "Spiral Knights" was positive. Ars Technica's Andrew Webster wrote, "The quality of free-to-play games continues to rise, and "Spiral Knights" is proof of this. It's fun, addictive..." Tony Sims wrote for "Wired", "It is very fun and addictive, however hardcore gamers might find it too old-school."
The game was nominated for the 2011 Game Developers Choice Online Awards in four categories: Best Visual Online Arts, Best Online Game Design, Best Audio for an Online Game, and Best New Online Game. It won the award for Best Online Game Design.
For the first two years of the game's general availability, playing time was restricted by the in-game commodity of energy. Tom Senior of PC Gamer wrote, "When an energy drought stops play halfway through a session with friends, it’s like being poked in the eye." However, the energy system was redesigned in the July 30, 2013 game update, and this criticism no longer applies.
Nick Popovich was the lead designer of "Spiral Knights" for all of its early development. On January 16, 2014, Popovich resigned his position at Three Rings, leaving the continuing development of the game to the rest of the "Spiral Knights" team.
On April 6, 2016, ownership of the game was transferred to the company Grey Havens. Grey Havens is a group of former Three Rings employees, which was founded to keep Three Rings games online. By July 2018 the game had over 5 million registered accounts through Steam. (This figure does not include accounts created through other means, such as the game's web site.)