Risk of Rain 2 follows a similar approach as the first title, in which one to four players must progress several different levels while killing enemies. On each level the goal is to locate a teleporter, randomly located on the level; once activated, the players must defend themselves from an onslaught of aliens, including bosses until the teleporter is fully active. Killing aliens gains experience and currency; the currency can be used to open chests that randomly drop items on the level. These collectible items offer a wide range of boosts to the players carrying them and provide both synergistic effects and the potential to stack their effects if multiple copies of the same items are acquired. However, the strength, difficulty, and numbers of aliens increase every five minutes, thus making the game harder the longer the players stay on any level. In the metagame, players unlock access to new playable characters, items, and game modifiers by completing certain in-game achievements; once unlocked, new characters or modifiers are available to select from at the start of the game, or the new items can start appearing randomly in-game. Risk of Rain 2 features several of the same playable characters, creatures, and items from the first game, but transitions the game from 2D to a 3D environment.
Development
In May 2017, Hopoo Games announced that they had been working on a sequel Risk of Rain 2 over the previous 6 months. The sequel was to maintain the same core loop as the first game. While the game was still at the early stage of development and other features might change, Hopoo affirmed that they were transitioning the game from 2D to 3D, as the 3D option provided "much deeper design spaces and more possibilities for cool gameplay" as well as more ways to artistically express themselves. When they started development on the sequel, Hopoo started with a 2D-based prototype with the player in control of one of the monsters in the first game, as to mix up the formula for the sequel. Part of the addition for this was inspired by Risk of Rainfan art that showed the various objects the player collected shown on the character, and Hopoo wanted to use this approach for the sequel, but the 2D graphic approach did not give them enough visual space to work with. They transitioned the prototype from 2D to 2.5D, representing the character in 3D graphics but otherwise playing as a 2D platformer, but when they completed that, they felt it was better to move the game fully to 3D, with the transition being relatively quick to complete. The sequel will use the Unity engine, which Hopoo had to learn for this, as well as the time in developing the 3D worlds. The sequel brought back most of the same classes of characters and monsters from the first game, but with modified or new abilities reflecting differences between 2D and 3D. Hopoo explained that some monsters that were difficult to avoid in the original game due to their size could easily be kited around with the added space of 3D, so they added additional attacks for these monsters to make them more difficult. The map design is similar to that of the first game in that there is random placement of the teleporter and other items along with different permutations of the same level. As of the December 2019 update, different versions of stages, called 'variants', were added so as to improve the replay value. Hopoo plans to improve the multiplayer options, including using Steam peer-to-peer connectivity, matchmaking including private matches, and split-screen play. Hopoo released the game into early access on Windows on March 27, 2019, for building the game's community and gaining feedback. Hopoo planned to provide frequent content updates to avoid a content drought while they finished development, a process they anticipated would take another year. During the early access period, Hopoo signed with Gearbox Publishing to release the game on Nintendo Switch, PlayStation 4, and Xbox One. It was also released in early access for those platforms on August 30, 2019. The game will fully release out of early access for all platforms on August 11, 2020.
Reception
On its launch into early access, Hopoo Games offered Risk of Rain 2 with a "buy one, get one free" promotion for the first few days. A week from release, Hopoo announced that over 650,000 players had played the game, with about 150,000 of those having taken advantage of the special promotion. Within a month of the game's early access release, it had sold over a million copies.