Let's first make it clear what this game isn't:
- It's not a city-builder;
- It's not an economy-focused game;
- It's not Stronghold: Polygons.

What is it then? Maybe something like a glorified tower defense, but with a catch. Or a few. Typically your goal is to survive a number of enemy "waves", which could be a finite number and after you defeat the last one, you win the mission. Or, you have to accomplish task X while defending against the said "waves". Task X could be to destroy the enemy base, to defeat a certain powerful enemy (i.e. something like a boss-fight), to find/free/escort someone and keep him/her alive, etc. That's pretty much it - nothing overly complex.

The game is not economy-focused because the economy is pretty simple. You have 6 resources - food, wood, stone, iron, gold coins and soul stones. The first 4 can be gathered from forests and nodes around the map, gold coins can be acquired only via trading and the primary source of soul stones are raids on enemy buildings (at a later stage you can generate a rather limited amount via a unique building). Gold is used for high-tier upgrades and the most powerful units. Soul stones are used for spells (of which there are 4 in total). Nothing fancy.

It's not a city-builder, because your "city" has a pretty limited number of buildings, the overall number of which isn't much higher than what you'll find in a StarCraft-like RTS. You have a few resource-production dwellings, a few military ones, some fortifications and other rather generic stuff spread around a few categories. Your goal is usually to make a well-defended base, which can keep you alive until you fulfill whatever your current objective is. As far as the defenses go, they aren't that many either - two types of towers and one type of wall, both of which have 3 upgrade tiers. There are also so some watchtowers and such that can technically be counted as additional fortifications, but to me they seem rather redundant.

It's not a Stronghold-like game, despite looking like one at a first glance, due to the above-mentioned details, and due to the fact that it plays generally differently. All the military units you'll command are nothing more than different versions of meat shields and ranged support, there is nothing special about them (even though they are not really identical and most of them play... some part on the battlefield) - maybe the only exception is a mobile bomb that you gain access to at the late game. You're not allowed to "peacefully" gather resources and build your base, repelling an attack every now and then - no, you're pretty much under constant pressure. Every next "wave" is more powerful than the last one and will eventually overrun your defenses no matter what you do, so you can't hide behind walls indefinitely - you're supposed to use every spare moment when the enemy horde is not directly in front of your walls to advance on the main goal for the mission, or to improve your defenses, if the given mission objective is to survive the final "wave". This is not a relaxing game at all. It can be called intense, fun, even tactical at times, but by no means it will help your mind find peace after good day's work.

What's good about the game? The way it's general concept is executed, mostly. It manages to achieve what it aims for - to provide you with a challenge and make you think how to beat it. You can be in a situation which seems impossible, but after you approach it from a somewhat different angle, it becomes doable, even if just barely. Admittedly that could be a downside too, because you may nee to restart certain missions several times to figure out how to beat them, or just because you discover that you'll inevitably fail because of something you did or didn't do much earlier.

The bad side is mostly the shadow of the good one - the game can be pretty difficult and frustrating at times. You're constantly bombarded with problems to solve here or there. A few enemy soldiers have breached a wall and have entered the settlement, razing buildings left and right, and whatever units you have around are picking their noses, despite the fact that the destruction might be happening right next to them. A citizen has died of illness (that might happen when you run out of food, or the said citizen walks past a fresh corpse) and if you don't bury him/her, a few minutes later rises as an undead and starts attacking everything. The resources of some type in the vicinity have run out at the worst possible moment, while you were busy fighting for your life elsewhere. The examples are many and tend to pile up rather annoyingly. On top of that, someone from the devs has decided that it's a good idea to be told that "The city is under attack", "They are attacking the walls", "The are attacking our citizens" and whatnot every few seconds - it can really get on your nerves during a tough moment.

There are a lot of other things that can be told - about the balance (which is far from perfect), about the graphics, the story and the (attempts at) humour, but that's details. The bottom line is - the game is good, but it's not for everyone, or for every time.

Gonna say this off the bat, in case it would have mattered to you, like it does to me, had I known. Door 407 is a Russian developer. Do with that what you will.

This game has some significant downsides. I'm going to start with those.
- The game does not have adequate information within or without to help players play better and more intelligently.
- The wiki that exists is woefully out of date, only containing information on the first two campaign missions.
- The game itself doesn't make understanding the game easier. Specifically, there are 3 weapon types. There is no discussion I can find on the multiple weapon types and their relative general or specific effects. I didn't even know that there were multiple different weapon types until I'd loaded up a sandbox mode game, and played some 400 days in it. Additionally, it appears that ballistae and catapults/ trebuchets have different damage types with values for their damage that doesn't make a ton of sense, intuitively.
- In the same vein, the campaign offers branching paths. It does not, however, help the player understand those paths. The ability the player has to go back and make a different decision is largely limited to a few "faction choice" named saves, but this is in the subtext of the save. Oftentimes if you go back to the faction choice save, you're obligated to re-play the mission to be given the faction choice again.
- The builder facility take at least 2 pop, and the upgraded builder buildings take 4 pop. From spending 600-ish days in a sandbox game, I noticed that the workers really only work where 2 workers = 1 build operation. My expectation was that 1 worker = 1 build operation. I kept wondering why buildings were not being completed as quickly as I expected until I noticed this.
- The transition phases between tech levels is painful and difficult to manage.
- Overall, the game is very difficult. Because the game doesn't help the player much at all, it can be quite difficult to understand where things started going wrong, so they can do better the next time.
- Cannot play as the Undead in an endless / sandbox map.
- The game ends up feeling pretty repetitive once the player has entered tier 3 technology.

The good:
- It's a very fun and engaging game. In typical RTS fashion, the game rewards building an army and being on the map to a much greater extent than the marketing material would lead a player to believe.
- The waves can be difficult, but build times on fortifications are typically not bad, and army movement speed can be pretty reasonable.
- Upgrades are clear cut and make a lot of sense. add a lot of value.
- Having infinite resources available on most - all maps helps a ton.
- The challenges one faces in each of the different branches of the campaign are different and have appropriate faction-related flavor.
- On the whole, the game is really fun to play. Endless doesn't appeal to me particularly, but the campaign (which I've played through a few times now) is quite fun. The difficulty scaling makes sense within the levels of difficulty I've played.
- Units regenerate on their own, and there are units that specifically heal other units. This is hugely helpful for making the game more accessible and fun.
- Siege weapons are hugely satisfying to use, both en masse and when they're given to the player at the start of a game.

To wrap up, Diplomacy is Not an Option is a fun game to play. Seeking information on it both inside and outside the game to play more intelligently is difficult. Because the game struggles to clearly communicate how it works, there are difficulties in periods that would otherwise be difficult but mitigateable(?), like transitioning from tier 1 to tier 2 and tier 2 to tier 3 tech. Additionally, in damage types and how those types affect enemies of different factions and classes. The upgrades system makes sense and is a great way to add dimensionality. Additional features, like infinite wood, stone, and iron are critical to making the game feel good the longer it's played. While the campaign feels not at all like the marketing material, with an army on the field being much more important than building walls and defending the keep, the blend between Tower Defense / RTS genres DNO seems to be shooting for is really well done. The campaign could also stand to have some UI improvements, making it easier to understand and re-choose which pathway to go down. It's a little disappointing that several of the choices put the player on the exact same track as they would have otherwise been. The campaign map has many more locations and landmasses that are as-of-yet unexplored by the campaign, insofar as I can tell. I would happily recommend this game to a friend, and have. But I do warn that if you'd rather not support anything Russian at this particular time in history, Door 407 is a Russian company.

Love this game so far. It is very similar to They Are Billions.