The short TLDR version: it's a great, strategy 'world game' with high production values, great MP play and covers the period perfectly. It's what RISK would be like if a group of Professors and history buffs modded the hell out of it and pumped it full of steroids. In fact, that's not far from the truth. Muzzy Lane are without doubt *the* academic game developers with an undeniable academic and gaming pedigree for historic sandbox strategy gaming. Their line-up includes MIT grads, noted world-famous academics and some of the best coders and designers around.
This is a well-researched, very well-constructed strategy game for thinking people and warlords alike.
While it's possible to go-for-broke and unleash the dogs of war from the start, you can also roleplay your nation historically (or ahistorically) and fulfil your desire for world domination, domination of a sphere, or run your empire or nation benevolently and attempt to prosper and grow. The game covers economic, scientific, diplomatic and military areas with detail and puts the controls of your nation at your fingertips.
Each power has it's own sphere of influence, and if you start becoming involved in areas of the globe in which they hold an interest, then you will be warned and war might even follow. It's a game where you cannot just bludgeon through without facing consequences. Armies must be supplied and also fed. Food plays a vital role (which is not covered in other games of Grand Strategy) and transport of that food is vital if you ship it from abroad. This is where control of vital areas comes into play, and also trade warfare such as unrestricted submarine warfare. You really have to think strategically in broad strokes to achieve your goals.
Also, the technology of the warfare of this period is unlike anything you may have been familiar with before. Warfare is in a new era that renders the old Victorian style of warfare (which didn't change much from Napoleonic times) obsolete. The machine gun changed all of this, making wars long, costly and with terrible attrition. A nation has it's War Weariness measured in the game, which affects the nation's will to fight. You can wrestle it out on long fronts, hoping for a breakthrough or you can try to end the deadlock by pouring troops into your meat-grinder and waging a war of attrition. Technology plays a vital role in gaining an edge, as new weapons and methods of waging war, like gas attacks, better artillery, assault troops and aircraft can turn the tide of battles. Eventually, one side will break and they will gain that extra territory. You need to make sure it's you.
There is also a wealth of demographic map overlays to satisfy the most obsessive map fiends. They cover amongst other things, religion, ethnicity, trade, infrastructure and so on. It's also worth noting that the economic and trade parts of the game are highly enjoyable and you can make a lot of money or gain precious resources this way. The market also reacts dynamically to supply and demand, so, you can do things like buy a lot of one resource on the market to drive the price up, and vice-versa. If you have the added privilege of owning major sources of that resource, then you can effectively destabilise other nation's economies without firing a shot.
The UI is typical for Muzzy Lane: uncluttered, easy to process, easy on the eye and with ease of access to all info in a very sleek and classy-looking way. You can go deep into the sub-menus for all kinds of interesting and vital info. The in-game encyclopedia is thankfully in-game and not online. This contains all info on unit stats, buildings, and everything else you would want to know. The manual also has extensive info on this and it's not a two-page leaflet with install instructions, a screenshot and key commands. It's a proper manual.
Finally, if you really want to create new scenarios, the editor will allow you to do this. You can recreate anything from the turn of the century to the inter-war period of the 1920's and early 1930's.
This period is very ripe for all kinds of alt-history scenarios and with bit of research you could make something really cool.
Or, you can cheat and give your nation a huge army, air force and navy, all available tech and then steamroller across the world if you like.
You can share the scenarios online through Muzzy Lane's website.
If you play global strategy games, then this is a game you must own.
I'll give it 9/10, one point off perfect, because I want to see them make a WW2 game like this.