An RTS:
General: full 360 spherical camera with zoom (this means you can look over, to the side, under, etc.). [I have no idea how to incorperate unit commands with a full 3-D environment] Also features possible 1st person shooter/flight simulater. This is done by taking command of a specific unit (any unit in the game, though it's more worthwhile for some, but most are just for fun; however, it's possible to take even the weakest armed unit and score huge number of kills despite limited power by using stuff like head-shots, taking cover, etc.). For Carriers and stuff with several turrets, however, you can concentrate fire at areas and guide shots for better accurecy. Weapons in 1st-person mode are fixed to what they got when they left the factory, however, so no salvaging weapons from fallen foes. In 1st-person mode, however, it's possible to hijack and commandeer stuff like tanks, mechs (really tough since they have cockpit shielding, but snipers are handy), and turrets. Upgrades also exist. However, after commiting an upgrade, the cost of cooresponding units also increases, like the Personal Ballistics Generator, which resupplies ballistic-using units automatically and on the fly, would increase the cost of units that use ballistics. Additionally, units that use bigger/more ballistics cost even more than one of a smaller/slower caliber.
Supplies are delivered using special transports that can use all styles of transportation (so some can fly, some are driven, some are submarines, etc.). These transports first stop by a supply depot to pick up supplies and then deliver them to units, with the number of supplies that can be carried depending on the efficiency speed chosen and the tech level of the transport. (this system was used in the game Earth 2150 and The Moon Project; but I'm expanding on the concept). There are also mobile refitters which can be supplied and they refit the units on the field (fix and resupply).
The beginning unit(s) are Commanders (lack of better term). They are the starting units of the games, and essentially the life-blood of the player (they are actually superweapons that can take down whole galaxies single-handedly when fully upgraded with their own personal set of ungodly expensive upgrades).
Unit weaponry can be individually customized with certain weapons before being set into factory building cues. Larger scale-units can be customized at any time given enough time to reset the weapons.
Size: Literally galactic-scale warfare (with some stages that span a gigantic area, almost literally universal scale). Can command single units the size of humans all the way to a fleet the size of an entire galaxy (or a superweapon the size of one). Due to the size of the ships, possible to employ small units (like infantry or small mechs/tanks) into bigger units as invasions from the inside and capture like that (or sabotage or even destroy, like self-destruction or destroying the main reactor). Can also use/built orbital platforms to attack planetary surfaces from the comfort of space. Planets are made small by this scale, but still necessary to conquer and maintain because they provide the best resource per area ratio. Also, planets can have weapons that can strike things from space, so a planet can be turned into one massive defensive fort (although possible to build space stations that act like forts as well). Will also feature stuff like Black Holes (essentially a massive neutral obsticle that can be destroyed, but will result in a utterly gigantic explosion, even by this game's size).
Unit to environment interaction: Everything in the environment is destructable, like Company of Heroes. However, since this is a much larger scale, this means even planets are destructable with a large-enough weapon. Even mountains can be flattened. If an explosive is big enough (but not big enough to wipe out the planet), it's possible to have an entire continant dropped below sea-level so where the continant was is now an extension of the nearby bodies of water. Also, there is real physics in the game, so a rail gun slug shot from space into the atmosphere (assuming the slug isn't annihilated during atmospheric entry) will slam into the land creating a massive crater and explosion due to sheer velosity. Impact size is effected by speed and density with size (some things with be large, but not necessarily heavy/dense; vice versa also applies). All planets have weather, which is effected by the ongoing action.
Weaponry:
Weapons are sorted into four categories: Ballistic (think bullets), Energy (lasers, etc.), Explosive (bombs, torpedos, etc.), and Experimental (see below).
Ballistic: Land-based weapons will consist of guns and shells that operate like nowadays weapons. Coil Guns and Raid Guns can be used on land and space battles, although it's a lot cheaper to use "current"-styled weapons for land battles. However, "current"-style weapons won't work in space (or places without an air density of a certain level, anyhow). Initially, all units that use ballistics need to be resupplied using supplier aircraft and stations until upgraded with the Personal Ballistics Generator. Very large scale units come already equipped with a Generator that can be upgraded (individually) to be more efficiant. Infantry cannot be upgraded with these generators, although they use a lot less ammo than other units. Good vs. everything, but not exactly top-grade damage
Energy: Lasers, electric-blast cannons, shockwave generators, energy cannons, EMP, stuff like that. Can be used on land and in space. Energy-based weapons have a "coolant" level instead of ammunitions, due to heat generated by firing. Coolant is supplied by supply craft until Personal Coolant Generator is researched. Damage is lower with range, but overall range is extreme with the damage reduction being fairly low. Larger scale units come pre-equipped with one that can be upgraded for better efficiancy. Best vs. units with explosives. Weak vs. shields and reflective armor
Explosive: anything that makes a big boom. Everything to stuff like shoulder-mounted missile launchers to interplanetary nukes. Smaller scale explosives ranging from infantry to large-mech size need a supply craft in order to get more. Must be supplied directly by a supply craft or a refitter; there are no personal generators except for carriers and extremely large-scale units (capital ships chiefly). Can be upgraded with various features, like homing for the smaller scale weapons or tactical warheads for the bigger ones. Best vs. heavily armored units and clusters of units. Weak vs. anti-missile probes and devices
Experimental: These are the most advanced and destructive weapons in the game, so powerful that they have to have their own category! Think Death Star powerful. Have to be built individually as a unit then the unit upgraded to carry the weapon. Some ideas I got are a Black Hole Bomb, which is basically an unstable black hole held in a time-space rift that breaks upon detonation. The Black Hole collapses upon detonation, releasing an explosion big enough to take out a galaxy at its smallest scale (some timed final missions with create bombs to take out the universe as a last-ditch attack). Others are planet-destroying rail guns (basically fires a slug that disrupts a planets weather and orbit until the planet explodes). Also, experimental weapons can be built in bulk, so surroud a guy with black hole bombs and make him think "FUCK!" before atomizing his entire fleet. Pwns everything.
Units: infantry, tanks, mechs of various sizes, aircraft, flying fortresses, bombers, space ships, space stations, carriers, cruisers, battleships, etc.
Resources: Just two. Stealing names from SupComm, Mass and Energy. Mass can be converted into energy and vice versa. Resources can be mined from planets and stuff like that. Some space stations can also supply amounts. Resources can be infinitely mined/generated. Also, some game modes will have infinite generated resources (stealing again from SupComm, "Infinite Wars"), where players basically build like mad to annihilate all that stand in the way. Also a storage/reserve in case of use>production. Short story: exact same resource system as Total Annihilation except mass can be turned into energy instead of that being only energy to metal.
Game Modes:
Infinite Wars: infinite resources generated, so don't have to build resources.
Annihilation: Destroy all your opponants and all of their units.
Political Overthrow: Capture at least one of the opponant's Commanders. Use of EMP weapons, special virus devices, and capture bots needed.
Spacial control: control the space around all the planets (planets don't need to be captured).
Planetary control: control all the planets (duh).
Whew...I think...that's all of it...
EDIT: woops, forgot about:
Music: fully orchastrated for that epic feel.
Carriers can be set to ferry (like SupComm) with factory rally points as well.
[If any of you haven't noticed, I'm mixing a bunch of good ideas from various games and putting them together into a behemoth]