Star Ruler

Star Ruler is a 3D real time 4X title from indie developers Blind Mind Studios. The game focuses on annihilating every other empire in the galaxy.

Research has a massive focus in Star Ruler - you unlock subsystems by researching its specific upgrade (i.e. researching Energy Weapons will help unlock lasers). However, when a subsystem is first researched, it's usually weak - you need to continue to research in that field to make it more powerful. Eventually, you research how to build Ringworld Planets, blow up stars in an instant, build ships larger than the galaxy, and make ships that can carry itself inside its own cargo bay.

Although it is completely lacking in narrative, its main appeal is probably... see the page image.

Star Ruler also has strong support for modding, with many aspects customisable in a humble text editor. Among the most popular of them is Galactic Armory, which makes quite a few substantial changes to the gameplay. GA tropes go into a separate section.

Tropes used in Star Ruler include:

All Planets Are Earthlike: Averted. Some are clearly not.
A Million Is a Statistic: Large ships have crews of over a thousand. The megaships that the player can build can have crews of millions. Planetary assaults with smaller (aka not planet killing sized death machines) ships result in millions (or billions, in the case of high level cities) being slaughtered indiscriminately by orbital bombardment.
Antimatter: It has has the advantage of needing almost no fuel storage, and mods add very efficient yet extremely powerful thrusters and weapons, but requires Antimatter generators, which are expensive and extremely fragile. Ships with antimatter tend to explode violently when their armor is breached.
Apocalypse How: Planetary assaults with big enough ships will cause the planet itself to break apart. You can then go blow up the star that the planet orbits.
Arbitrary Maximum Range: Weapons all have relatively small maximum ranges - but the ranges are measured in AU (Astronomical Units, basically the average distance from Earth to the Sun)
Armor-Piercing Attack: There are weapons that partially or completely ignore armor, but deal less actual damage.
Artificial Stupidity: The AI thinks nothing of it when a neutral player warps his entire fleet into their home system.
- Large ships tend to spend huge amounts of fuel chasing down small, unarmed scout ships.
Artistic License Astronomy: The orbits of planets do not affect each other, nor will ships. It's possible to have a station the size of Betelgeuse orbiting a planet not much bigger than Earth. Likely for the best, though - otherwise, planets would be shot out of the galaxy by players warping their ships everywhere. Fridge Brilliance: By the time you're building those megaships, you probably have some levels in Gravitics control.
Asteroid Miners: Asteroids can be mined by ships with Mining Lasers. Some "systems" are actually just a very large asteroid without a star, with some debris scattered around it.
Astronomic Zoom
The Battlestar: Ships can mount any combination of weapons and ship bays. With Quantum Space Compressors, you can have Clown Car Bases. Behold.
Bigger Is Better: Used and averted. While almost everything improves with size, various disadvantages such as reload times also go up.
Bigger Stick
Boarding Party: Boarding pods can be used to take over enemy ships. It's very effective to swarm enemy mega-ships with thousands of boarding ships. You can also make boarding pods have several thousand marines on them.
Boring but Practical: Railguns, which are the bread-and-butter weapon of the game. At small sizes, they're great against fighters, and at large sizes they can wipe out millions of people in one hit against a planet.
Bottomless Magazines: Averted with kinetics; when designing your starships you must take into account how long they can fire with the ammo stocks they have on board and add more ammo caches if they do not pack enough. Or you could design dedicated ammo colliers and send them with your expeditionary forces, but best hope the enemy doesn't shoot them first... Energy weapons on the other hand have no ammo requirements. Later research allows you to unlock the Matter Generator, which can generate ammo; with a high enough research level you can generate more ammo than you expend, conforming to this trope again.
Clown Car Base: The usual result of high-level Spatial Dynamics research. See above entry under The Battlestar. Even without it you can build ships or stations bigger than the constructor used.
Command and Conquer Economy: Used and averted. While you need to manually order the construction of ships, you can set different types of Governors to automatically build structures to your specifications (food planet, metal factory, et cetera) on the planets you colonise.
Deflector Shields: One of the early subsystems to be unlocked. Shields are very light (unlike Armor) and regenerate (only one type of armor auto-regenerates), but shields require large amounts of power, and as the shield looses "health", damage can bypass it and hit the ship's subsystems directly
Design-It-Yourself Equipment: The ship design menu allows you to set the size of your ship (anywhere from smaller than a can of Coca-Cola, to larger than the galaxy)), place subsystems (armor, engines, support equipment, guns, storage bays, etc), and set how the AI handles targeting and automation (automatically distribute goods, automatically refuel, etc)
Earthshattering Kaboom
Faster-Than-Light Travel: Of the Jump Drive variety. Ships without the drive have to go the slow way - flying to the target star on their own engine power. It should be noted, though, that "slowboating" can also result in low-end FTL - a light-second is roughly 0.002AU, yet ships can accelerate past that fairly early on.
Fragile Speedster: Ships with "Fighter" or "Bomber" hulls, and scout ships (typically smaller than a soda can).
Frickin' Laser Beams: A weapon choice. Averts the usual depiction by being continuous-beam and hitscan, though it gets ridiculous when you research them to where their range is measurable in AU (~8 light-minutes/~500 light-seconds) and STILL hit instantly!
Game Mod: The game is easily modded to include more subsystems.
Ghost Ship: Crew death, loss of power, or running out of fuel will cause a ship to go derelict, and drift until it's destroyed by the game several minutes later. Derelict ships can be salvaged and reclaimed if it's only the crew that died - doing so on an enemy ship will also allow you to steal the design and build it yourself.
Glass Cannon: Ships with little/no armor, but a very big gun. Works well when the gun is paired to a Targeting Computer, allowing it to fire much longer distances.
Higher-Tech Species: Remnants at first, though you'll overtake them eventually in most aspects.
Inertial Dampening: Appears to be present, as to stop human crews from becoming human paste on the walls when their ship suddenly accelerates at 100 g.
ISO Standard Human Spaceship: All of the ships models follow this design philosophy.
Jack of All Stats: Most of the default ship designs fall into this, being very balanced in its armor, weapon, and engine loadout.
Kinetic Weapons Are Just Better: Initially they are, but energy weapons improve such that a parity of sorts is eventually reached.
Lensman Arms Race
Macross Missile Massacre: With enough missile research.
Magnetic Weapons: Railguns.
Matryoshka Object: You can build ships that do this - be it smaller ships carrying progressively smaller ships, or if you're crazy, making ships carrying progressively large ships inside each other. With about a dozen transitions at high level Spatial Dynamics and Cargo Storage, you could go from a size 1.0 fighter to a size 256 battleship.
Mighty Glacier: Ships with lots of armor and/or weapons, but small engines. The ship has no top speed, but it'll handle like the state of Wisconsin, and have trouble getting to its destination in a reasonable amount of time. However, it'll be able able to absorb tons of damage, and instagib much of what dares to attack it.
Mike Nelson, Destroyer of Worlds: Some time in, you will be building and facing ships more durable than planets and with the firepower needed to destroy each other. This can easily mean that you target a planet to cleanse it of enemy life and end up accidentally fragging it because you underestimated just how just firepower you have in play.
Min-Maxing: At game-start you can choose traits for your faction through the juggling of points.
Mobile Factory: Placing a Mining Laser, storage, the 3 part refineries (Metal, Electronics, Advanced Parts), and a Construction Bay on a ship will allow it to start building ships once it has an asteroid to mine. It's possible to build what are essentially Von Neumann self-replicating ships using this - order them to build 10 of themselves, then order them to mine a large asteroid. Keep repeating this, and about an hour later there will be several hundred ships mining the asteroid.
Necessary Drawback: A key part of the game design; new subsystems unlocked through research are not just incremental improvements on the existing ones but have their own flaws to balance the advantages they bring.
One-Man Army: Due to military strength calculations, one mega-battleship can be worth whole fleets.
Point Defenseless: Averted for the default ship designs, which typically feature Flak Cannons. However, many of the hostile AI ships (Pirates and Remnants) lack them.
Portal Network: The Remnant Gates allow ships to instantly teleport to anywhere in the galaxy.
Ramscoop: One of the possible propulsion methods. Ramscoops have the advantage of using zero fuel, but they have very low thrust.
Regenerating Health: Crew quarters provide a small amount of regen. Repair bays give you more regen. Nano armor repairs itself, but does nothing for the rest of the spacecraft's systems.
Ringworld Planet: The player can eventually research how to build ringworlds. They take several gigatons of material, and will take several real-time hours to build without sufficient infrastructure, especially if you're fool enough to try and build them as soon as available.
Rock Beats Laser: Hyper-averted. A technologically advanced empire will absolutely crush a lower level empire. To emphasize this - A fighter with level 40 armor, engines, and weapons will curb stomp a level 1, mega-battleship
Sci-Fi Writers Have No Sense of Scale: FTL travel through pure acceleration and FTL lasers. Enough said.
Space Fighter: Present. Very cheap and fast, but thoroughly useless at killing most enemy ships beyond size ~50 without a large tech disparity, though they make very good cannon fodder to distract enemy guns.
Space Friction: Averted, hard. The game utilizes newtonian physics, so ships will need to use fuel to both speed up and slow down. If a ship runs of out of fuel mid-flight, it'll just keep on drifting towards its destination, then keep on drifting past it until the effects of space dust destroys it.
Space Pirates: Pirates will occasionally attack poorly defended systems. As such, it's best to have a small garrison force on each system, or a big carrier with a jump drive for fast response.
Space Station: Player designs usually fall into either "Defense Platform" or "Dry Dock". Space stations armed with weapons have the advantage of being ridiculously hard to kill, and Dry Docks don't have the labor requirements to build ships (or other stations) like planet based shipyards do. It's also possible to build refinery or trade docks. Refineries will take Ore from the planet, and refine it to Metal, Electronics, or Advanced parts, allowing the planet to focus entirely on just mining out the ore. Trade Docks will simply take material from the planet and put it into the "Galactic Bank", which any planet with a Space Dock can get materials from.
Standard Sci-Fi Fleet: Everything present larger than an escape pod. Fighters, bombers, corvettes, frigates, haulers, tanks, battleships, carriers, Battlestars, Motherships, ships the size of the galaxy...
Star-Killing: Pump enough energy or several teratons of ammo into a star, and it will go nova. Once your tech level is high enough, it's possible to one-shot a star using a planet sized ship.
Stealth in Space: There is stealth tech, but all it does is make ships harder to hit.
Subsystem Damage: Damaging enemy ships will cause their subsystems to fail (destroying their generator, ruining their ammo cache, killing the entire crew, etc) once you get past their armor - which is also a subsystem.
Superweapon Surprise: Save for capturing enemy ships or finding derelict ships, it's impossible to know how advanced an enemy is - leading to things like a enemy fighter wiping out your battlefleet because you weren't researching. Additionally, it is not possible to view how many ships an enemy planet or ship has docked. You could be invading a ripe, undefended system... only for hundreds of enemy battleships to come pouring out of the planets to wipe out your battlegroup.
Tractor Beam: A pulling (and pushing beam) are available as subsystems. Largely pointless, but they can be used to grapple onto enemy stations and pull them out of orbit, or send enemy ships catapulting out of the system
2-D Space: Planets will always be along the ecliptic plane, but stars are all at different "heights" along the Z-axis, and player ships can fly in any direct - holding down a button while giving a movement order will allow you to order them to fly up or down as they move to their destination. Attacking from above a system is effective, as you likely will not come into range of any enemy orbital defense stations.
Units Not to Scale: Units are to scale with each other, but not celestial objects (planets, asteroids, stars). A size 2500 station is several times the size of a planet, but will have a crew around ~200,000, whereas a planet will have a population of about a ~100,000,000 at low levels. This is present to ensure that your ships are actually visible at a decent zoom level.
Universal Ammunition: All weapons draw from a source of ammo with no attempt to distinguish.

Galactic Armory adds or changes the following examples:

Abusive Precursors: Remnants are changed into this from vanilla. It's unknown how they were like before, but nowadays the artificially intelligent remnants of their vast fleet attack anything in sight. Unlike in vanilla where they were content to bum around in their systems and chase the kids off their lawns, GA's Remnants send out roving kill-squads to purge the younger races every now and then.
Armor-Piercing Attack: There are now weapons that are great at killing shields, but...
- Crippling Overspecialization: Don't do jack against physical things like armour or hull.
The Battlestar: The mod adds two hulls meant for this; the Carrier Hull, like the name suggests, leans more to normal carriers in being relatively thin-skinned and trades some space away for having strikecraft bays integrated right into the hull, while the Mothership Hull is closer to a Battlestar, trading out some space and not having the option of extra ship bays in order to accommodate more weapons and stuff.
Fixed Forward-Facing Weapon: The Spinal Mount Hull lets you make these.
Honor Before Reason: One Trait you can take is "Code of Honor", which prevents from using a variety of subsystems. No WMDs, fair enough, but when the thing prevents you from using sensible things like Armor-Piercing Attack it goes straight into this.
Macross Missile Massacre: Missile numbers scaling with level has been removed, but there are now Barrage and Cluster launchers.
Min-Maxing: Taken to a new level with added Traits that allow you to improve or worsen certain weapon types, further encouraging you to specialise your research than in vanilla.
Outgrown Such Silly Superstitions: One Trait allows you to invert this. It prevents you from using certain esoteric tech, most to do with Spatial Dynamics, with the reason that your people's religious beliefs forbid it.
Point Defenseless: An explicit PD efficiency mechanic has been added. It caps out at 80%, meaning that statistically you will never have perfect PD.