It incorporates multiple unique races with different mechanics rather than the Cosmetically Different Sides of the previous game:
- Terrakin - A human Lost Colony. The most average of all the races with no large strengths or weaknesses.
- Oko - Plant People. They do not build cities and colonize planets via massive spores, and must bind their ships together with biomass.
- Hoonan - Cyborgs. Their ships become stronger the closer they are to orbital mainframes.
- Feyh - Clap Your Hands If You Believe. Their ships contain shrines that protect them from damage when manned, and they can stuff more people into smaller spaces so long as they pray.
- Saar - Space Mormons. Rather than orbital outposts, they construct missionaries that send ships to allies and their own planets for bonuses.
- Mono - Robots. Can instantly colonize planets, but cannot make use of orbital shipyards and must build new population from planetary labor.
- Nylli - Space People. They do not utilize planets, but instead build orbitals around it via massive motherships to extract resources.
- Heralds - Intergalactic refugees, added in the Expansion Pack. They colonize via refugee ships jumping in at random, and can send resources back to their crumbling civilizations for bonuses.
- The First - Post-physical virtuals added in the Expansion Pack.
Like the original, it has a heavy focus on the Design-It-Yourself Equipment, allowing players to make ships to take any size - from a Coke can to the size of the galaxy - or function, from Asteroid Miners to planet killers. The Unstable Equilibrium research system of the game has been significantly toned down, with flat bonuses rather than the continuously scaling bonuses.
It strives to avoid the Command & Conquer Economy, with most planetary buildings being built by the demands of incoming imports via the "Pressure" system; export metals to a planet, and it'll build factories. export artifacts, and it'll build research centers. Only the absolute largest planetary structures require the player's intervention to build.
Diplomacy takes the form of a large minigame of sorts; players propose a treaty such as investigating another player's territory, which all players can vote on and attach riders and clauses to by expending Influence. You can even force votes through to annex other player's territory; it's for the greater good, after all. The often brick-headed and stubborn AI of the first game is far more cooperative and can form alliances or submit to aggressors, becoming a puppet state.
For the original game, see Star Ruler
Star Ruler 2 provides examples of:
- 2-D Space: Fleets align themselves along the galactic plane, though ships can drift out of alignment and debris will fly in whatever direction it pleases.
- Arcology: A mid-game research allows you to build imperial megacities that go from below the earth, all the way into the sky.
- Artificial Stupidity: By default, Remnant fleets do not chase down ships and will not try to glass planets being colonized in their system, only shooting at ships that approach. Their engagement AI can be re-activated with an option in the prematch setup.
- Big Dumb Object: Neutral "Seed" ships will occasionally build unique upgrades that players can steal and utilize, such as a massive telescope to spy on several systems at once from across the galaxy.
- The Dog Bites Back: The Influence system in SR2 allows losing (but influential) empires to use diplomacy against their aggressor.
- Easy Logistics: Ships immediately receive researched stat bonuses when within friendly territory, to counter the ad-infinitum retrofitting that plagued SR1's endgame, where the ships you produced were obsolete within minutes. Ships still need to be near a friendly planet to reload their "Supply" (ammunition, fuel, etc) and restore their support ship roster.
- Expansion Pack: Wake of the Heralds, which adds two new races - the Heralds and The First - a new type of Faster-Than-Light Travel, new technology, an attitudes system that causes ones actions' and political alignment to add bonuses or maluses, and a cooperative survival map.
- Faster-Than-Light Travel: Several flavors, all of which require FTL Energy, which is a global resource that is slowly built up and can be stored -
- The Mono assemble jump gates (previously, only Remnants possessed gates) which must be flown to their destination, then stopped before being linked up, which will then provide instantaneous travel between any gate. This is also the only method that can be used for trade.
- The "Fling" beacons used by the Oko can catapult a ship extreme distances for little energy, but can only be mounted on orbitals - in essence, you fire your ships at their destination like a railgun - once a ship reaches its destination, it has to rely on standard thrusters for movement or its return journey unless you have another beacon there.
- The Hyperdrives used by the Terrakin and Saar function much like the warp drive in Star Trek - it's faster than slowboating with thrusters, but still slower than everything else, and consumes energy as the ship moves through hyperspace.
- "Slipstream" drives on Nylli ships allow specialised ships to tear a hole in reality, like in Halo, through which a whole fleet can instantaneously pass through to the paired tear, although unlike gates the tear is temporary and can be used by enemies.
- The Herald "Jumpdrives" added in the Expansion Pack have instantaneous travel time but have limited range and requires an expensive module to be attached on ships unlike hyperdrives. The Heralds can jump to their intergalactic jump stabilization beacons regardless of distance.
- Lighter and Softer: The sequel has a more lighthearted art style, with bright and colorful UI and race portraits.
- Shout-Out: The achievement for destroying a Seed ship is "A Different Destiny"
- Small Universe After All: The game allows for the generation of multiple galaxies, but if star counts are high, performance will obviously take a big hit even on high end systems.
- Space Elevator: A planetary project. Elevators are very expensive but cut the cost of support ships by 40%.
- Starfish Alien: The old defunct race portraits from the beta, bar a single Humanoid Alien who lacks a mouth or nose; one race appears to be a rock with eyes and several other rocks covered in goop. The newer profiles are a bit more normal (having actual heads) but still very nonhuman.
- Subspace or Hyperspace: Hyperdrives allow a ship to move at phenomenal velocity, much faster than standard thrusters, but consume energy as the ship moves.
- Unstable Equilibrium: Sequel Escalation from the first game. Early rushing to grab as many planets as possible is even more important than before, and this time there are no Space Pirates to prey on weak colonies to discourage you from going wild with the colonization. However, the crazy scaling researching bonuses of the previous game has been significantly toned down; players are no longer completely helpless against a more advanced empire.