Age of Empires - European Steel
This is age of empires! Which mean it follows the theme of an RTS that advances through usually about 4 - 6 ages of infrastructure and technology.
In WW2, ages reflect your army's budget. Although this game is WW2 themed, the events of history don't necessarily mirror WW2 in any way, and attempts to fully recreate every event of WW2 would be troublesome with this system.
In this sense, a 1v1 match of players could be France versus the US (example).
Villagers are pioneers, which can turn themselves into combat engineers on the fly.
Every infantry is a soldier, usually with a fire arm, some special ability, body armor, or a unique weapon or role (ie. mortar crew, gunner, bazooka, rifle, grenadier, etc.).
Monks are called chaplains. They carry a light kit (usually a rifle or something).
Cavalry is light vehicles and tanks. They have explosive shells.
Siege is artillery.
Close ranged siege (ie. the battering ram from age of kings), is heavy tanks and heavy vehicles. They have bombarding shells (longer range), machine guns for close range, and include APCs with their own machine guns (a vehicle with ramming capability).
There's an air force and a navy. Air force doesn't have great force projection by itself beyond anti-air defence and risky ground defence. And then there's combined air force and navy, which is the ultimate force projection.
GM can create any number, however, the primary loss condition is having no city halls. With no center of politics, your people are (somewhat ironically) divided in loss of confidence and war cannot continue.
Age limitation! The game can change completely, depending on what the minimum/maximum ages are.
What are all the ages?
Depression Age - Nothing much happening. Everyone is poor (don't get much from pioneers beyond menial labor). Get money from capturing rail roads, and basic industry (mining, ie.). Get food by trading. Get petrol and metal by scrounging and stealing. Find weapon caches to get a quick boost of infantry.
Rush Age (requires 500 food, 500 money and a City Hall) - Build forts and the like faster. Get money from higher industry (weapons and ammo manufacturing, sea transportation, ie.). Still have to worry about defending your merchant ships!
Bond Age - Age of warbonds. Lots of money comes through loans (get some money right away, pay back a little more later). With lots of money, you can get your mech on the road (from sea to shining sea).
Armor Age - Get a decent fleet of vehicles and ships. Now you have the ultimate force projection! Germans, of course, get cheaper U-boats at this age.
Alarmist Age - Defence from air strikes. Pioneers can garrison quickly. Population centers suffer less from carpet bombing. Mighty forts. Precision bombing doesn't affect your garrisoned armies as much any more. Good for 'turtling'.
Nuclear Age - Super bombs. More than just nukes (nukes are expensive in misc. and money!).
Food. Mostly for infantry and pioneers.
Money. Use it on the market, and nothing else.
Metal. Mostly used for forts and ships. A little bit is needed for vehicles.
Misc. Gifts of Nature (MGN; Ie. wood and stone). Used for pretty much any structure or special homefront ability.
Petrol. Use it to purchase vehicles, air planes and ships.