Icarus (also known as Icarus: First Cohort) is an open-world session-based Survival Sandbox game with Roguelike elements. In standard gameplay, the player's avatar character is sent to the surface of Icarus to accomplish one or more mission objectives within a strict time limit. If the player accomplishes their goals and extracts safely, they gain currency with which they can outfit their character for future missions. If they miss their extraction time, they're left on the planet to die in the next megastorm. Notably, players' structures and technological development aren't maintained between sessions, requiring the player to restart from the ground up every session. A continuous-play mode more reminiscent of other Survival Sandbox games was added after release.
Far in the future, humanity is ambitious and technologically advanced. After using engineered enzymes to recover from an unspecified "climate emergency" on Earth, they set their sights on the stars, finding a moon with a near-Earth climate, and used similar processes to terraform it with an eye toward colonization. The terraformation didn't take, though: The atmosphere is toxic to humanity, cataclysmic weather frequently wracks the surface, and if that weren't bad enough, the wildlife (whether transplanted or native to the planet) is often strange, wild, and hostile. The failure led people to call the place Icarus. The attempt would have been abandoned, save for the discovery of valuable exotic materials on the surface of Icarus. Hopes of colonization had fallen, but the call of wealth draws a stream of prospectors to the world.
This show provides examples of:
- Ability Required to Proceed: Downplayed but present. Certain areas of the planet face environmental hazards - extreme cold, searing heat, toxic swamps - and trying to explore those areas without technology to mitigate the effects is a great way not to survive the mission.
- Adaptive Ability: Something in Icarus's environment - the terraforming enzymes, the exotics, or something else entirely - has mutated the wildlife of Icarus, both natural and imported from Earth, to be immune to the toxins in the atmosphere. The mutations also seem to have heightened many species' aggression to near-suicidal levels.
- Air Containment Field: Averted. The prospector never removes their containment suit, and must use oxite mined from the environment to produce oxygen to breathe.
- Artistic License – Biology: Some of the indigenous creatures of Icarus are... biologically unlikely. Especially notable are the creatures living in the Lava Flow biome, who have made a happy home in the middle of flowing magma fields.
- Attack Its Weak Point: Most of the creatures on Icarus are vulnerable to headshots, or have other vulnerable spots that will suffer increased damage when targeted.
- Bizarre Alien Biology: All over the place. Between the Drifters who float through the air like jellyfish and the aforementioned lava-dwelling creatures, Icarus has its share of exceedingly unusual wildlife.
- Boring, but Practical: No matter how many advanced firearms you develop, archery remains viable for long swathes of the game due to the relative ease to obtain and craft the ingredients.
- Company Town: In a way. There are several competing factions vying for power over Icarus, from the ambitious and far-reaching Sinotai to the mysterious Group 15, but all human activity on or around Icarus is controlled by one or more of these factions.
- Convection, Schmonvection: Build a dirt foundation bridge right over the surface of an active lava flow? No worries, you can skip over the thing and you'll be fine.
- Early Game Hell: Especially for session-based play. Get ready to build a lot of thatch buildings over your gameplay experience.
- Equipment Upgrade: Once you get the appropriate upgrade station, you can improve the statistics of your crafted weapons and armor.
- Everything Trying to Kill You: Even the local horse analogs are aggressive.
- Hostile Terraforming: The processes that were used in the attempt to terraform Icarus were deadly to large swathes of the population, even discounting the malfunctions that led to the toxic atmosphere. As revealed in the New Frontiers DLC, this includes the extinction of an intelligent species which had previously lived on Icarus - and which Group 15 had known was there.
- In-Universe Game Clock: There's a day-night cycle and a countdown until the dropship leaves (while in session mode). Noteworthy, the two clocks aren't synced; the Prospector can sleep to skip the nighttime without missing out on a swath of time to complete the mission.
- Item Crafting: You'll be crafting a lot in this game: weapon, armor, tools, workbenches to make other weapons, armors, and tools...
- Item-Drop Mechanic: You can use a knife to harvest most fallen fauna for materials - mainly meat, leather, fur, bones, and the like.
- Item Farming: You'll be cave-diving for minerals and hunting critters for food and other materials throughout your missions on Icarus.
- Late to the Tragedy: Some of the missions you can undertake have you tracking down other agents, either to save them or to apprehend them. If you're able to find them at all, it's always in corpse form.
- Mission Control: A gruff-but-friendly feller named Sol Berlinski gives the player information about missions they encounter, and often chimes in about the creatures the player encounters. Occasionally, when the player does a mission for one of the factions vying over the world, they'll provide their own (generally much-less-friendly-and-trustworthy) mission control.
- No Biochemical Barriers: You can eat the food on the planet. On the other hand, the air is a deadly poison, so....
- Numbered Homeworld: The official name of the gameworld is Wolf 1061ca. These days, most people just call it Icarus.
- Oxygen Meter: The character needs to provide oxygen to their suit to survive. The simplest way is to mine up some oxygen-offgassing oxite and place it in the containment suit. More complex methods require using various workstations to distill and bottle larger quantities of oxygen to carry around.
- Patchwork Map: The map is made up of a number of biomes, from the relatively-placid forest to the tundra to the lava flows.
- Sound-Coded for Your Convenience: You'll quickly learn to recognize the growls and snarls of the various aggressive pieces of local fauna.
- Timed Mission: All missions have a time limit, counting down in real-time. The earlier versions of the game had the timer tick even when players were offline, which was later changed to only count down when at least one player was connected.
- Weather Gameplay Mechanic: The game has a weather forecast for general weather temperament, and weather events that are an environmental hazard to colonists out in the open (which may also damage buildings).