I would just like to know if there is an input email or thread or something that the designers will look at before making the initial/final gameplay decisions, since they are essentially in phase one.
Here are some thoughts:
Tiles
Landmark Forests: 1 forest tile per city can be designated as a park reserve/national forest. This would only produce commerce & give culture points, but would not produce food or shields, and could not have a railroad or mine built on it.
Forest Planting: Planting forests can help slow global warming. Also see United Nations. This would keep forest chopping for shields in the early ages, but promote forests in later ages.
Bonus Tiles: can be depleted like other resource tiles.
Coastal Waters: Can now contain and be mined for oil by dispatching a new naval unit to it (designers choice) and having it work like a colony does now.
Rivers: Workers can 'dam' a river for many turns. This can only be done once per river & once per city, but would create a 1 tile freshwater source on the tile that was dammed. Workers would be moved to an adjacent square upon completion.
Canal/Bridge: A 1 tile only bridge may be used to connect locations such as the modern day Panama Canal & Bering Straight. The canal can not be adjacent to a city or other canal & must connect 2 water tiles that are opposite of each other in respect to the canaled tile. The bridge would do the same for land, but must take place on a coastal water tile. The bridge could be built by the same new ship that constructs an oil colony (see Coastal Waters)
City tiles: 1 turn delay when moving population from a mined tile to an irrigated tile, and vice versa, in terms of productive gain.
Leaders
Cultural: A Cultural Leader with the ability to rush a Great Wonder (or smaller building), or create a National Monument in a city (one per city max) that gives culture points and adds tourism. This would be tactical in a border city if trying to culture flip a city, raise culture in a newly conquered city, or promote a cultural victory. These leaders would have a chance to spawn from (non-capitol/forbidden capitol cities with an extended 'we love the king' day, winning a war, 'x' turns without corruption, or positive UN action).
Air/Naval: see Air/Naval Elites
Units
Elites: Elite winning units can spawn Great Leaders or can be promoted into 'Special Forces.' These Spec Ops work like Privateers, but on land (ie - no nationality revealed).
Air/Naval Elites: Can become Squadron Leader/Flagship and be treated as Military Great Leaders (ie - build army), with maybe 1 less unit per army then ground troops allow (to keep things reasonable).
Refugees: A city may release a refugee (1 population point) that will migrate to a high cultured neighboring Civ. This would replace or maybe preceed the current Cultural Flip.
Conquered Civ's: Remaining units become Refugees, Barbarians, or neither.
Barbarians/Terrorists: Barbarians can evolve with the times. They will contain units that are '1 step' below that of the average Civ's best unit for their elite spawn, and lesser units for secondary spawn. Their camps can spawn in any land tile not used by a city, even if it's within a country's borders (ie - a culturally gained square). Camps are more likely to spawn next to cities with high corruption, or which were recently conquered.
Land Transports: Helicopter (treated like a land unit traveling a road) that can travel any land square other then mountains & can hold up to 3 units.
Attack Chopper: Apache style chopper (treated like a land unit traveling a road) that can travel any land square other then mountains & coastal waters, and is a Modern combat unit.
Game Features
Civil War: If corruption is too high and there is room for another Civ, a Culturally-Linked Civ will spawn in the corrupt cities. This Civ will take control of those cities. The units inside will be demoted, or left the same but at smaller numbers, or altered to guerillas/other offset units. Since this new Civ will have relations with the other Civs, the relations will be reversed from the Original Civs relations with those Civs (ie - Civ A's allies become enemies to Civ B, and vice versa).
World War (varying on map size/Civ opponents): When multiple Civs are in a large war, there is a chance for it to become a 'World War.'
Example- Let's assume there are 12 Civs in a game. Civ Z invades Civ A, and is therefore noted as the 'aggressor.' Another Civ joins the fight via an Alliance, which team doesn't matter. The other Civ calls forth it's own Alliance, and this continues to a set number. Let's say the number is 6. Once there are 6 Civs involved (assuming there are at least 2 Civs on each side & no same side Civ's are at War), there is a chance for it to become a 'World War.'
(A + B) vs Z
(B + C) vs Z
(A + D) vs Y
A vs (Z + Y)
A, B, C, D are aligned on one side & Z, Y on the other. Since Z was the aggressor, that side is dubbed the 'Axis' & the defending side (based on A) becomes the 'Allies.'
Now say Civ's E, M, N are neutral. Civ E decides to ally with D against Y. Since Y is part of the Axis, and D the Allies - this makes E part of the 'Allies' and are now allied with A, B, C, D against Y, Z. On the other hand, if Civ D allies with M against N, since M/N are not part of the World War, this becomes a separate affair.
Winning Civs gain Culture Leaders (or high chance of).
I know it's a lot to think about, but it's easy in terms of programming - all just IF/THEN scenarios.
Diplomacy
United Nations: Small Wonder or Modern Advancement leads to committee vote. Must contribute 10% of military units to UN (your choice, but in a given time), or lose vote/seat in UN.
UN votes on stopping wars, preventing Civil Wars, Becomes Allies in World Wars, can demand all Civs to set aside x% of land to forests to fight global warming (see above), demand Civ to destroy Nukes, make peace with other Civs or face UN troops (UN works as AI Civ who always forces peace), etc.
Civs: Can trade military units, not just workers. These units are demoted if infantry, armored units trade as is.
Can also demand peace be made by warring Civs (with or without UN).
Techs
Space Victory: Moon base, not spaceship - more realistic.
Satellite: updates 'x'% of map over 'y' time. Small Wonder?
Space Capsule: Small Wonder that works with other Civs capsules. Example- First Capsule is Space Station. Each additional capsule (1 per Civ) connects to International Space Station. This improves relations with those Civs. Each capsule itself also gives a tech bonus (say 5%), plus (say 1%) more per additional Civ capsules added to it (no more then 8% total). Must have a capsule in ISS to make a Moon Base for Space Victory?
Historical Relations: If 2 Civs have been at peace for the extent of at least one full Age, past wars become 'forgotten' - improving relations. Example- Civ A & Z war in Medieval Age, but declare Peace before the end. As soon as one completes the Industrial Age (assuming they remain at peace), the old war memories are gone, and relations improve (other Civs no longer say "we remember how you treated [Civ A]").
Traits: Each Civ has one neutral trait, but also one trait that is exclusive to another. This means certain Civs will always be at some odds (a vegetarian society would look down on a carniverous one, etc).
Other
Combat: Troops over-run forces that are more then an Age old (or even 2). Example- Spearmen are from the Ancient Age, Armor from the Modern Age. Since there are 2 full Ages between them, the spearman is over-run.
Workers: When set to auto, you can toggle which options are okay (ie - auto: road-on, irrigate-on, plant forest-off, etc).
Cities: Abundant supplies can be shared with another city, if a trade route is established?
Just some suggestions...