I personally managed to get in on Thursday and after somewhat extensive testing(Up to tier 4 in at least two branches), I approve of almost everything about it.
Divided into two parts, the gameplay and the progress metagame, the gameplay is almost perfect. The metagame seems unfinished, but as long as they continue on this path and don't add too much unnecessary trash it should be just fine. I expect the progression to be a lot slower in the final release though. It's obviously sped up for testing.
Wall of text, incoming.
The game is divided up into 4 classes:
Destroyers - Not a Light Tank
These are NOT light tanks. This is not tank game, this is ship game. These are fast, they are fragile, they sort of specialize in concealment, but those are the only comparisons you can really make. The guns tend to be relatively weak and few, especially on the Japanese destroyers. Almost don't bother firing except at another destroyer. Obviously any damage is good damage, so fire when appropriate, but if you're not positioning for a torpedo attack while firing, you're doing it wrong.
Torpedoes
Their real weapons are the torpedoes and their special, the smoke screen. Torpedoes are absolutely devastating. I've never seen a destroyer survive a single torpedo. Most cruisers sink in a little over two. A full salvo from any but the lowest tier destroyer will basically take out any battleship. They're fast, some destroyers have a dozen or more of them to launch at once. They're ALMOST overpowered. But you always know, in general, which direction they're going to be coming from if you're paying attention and while I hear the range gets better in later tiers, so far, all the torpedoes I've encountered have required you to get well within the firing range of enemy ships before they can be launched. (Most guns at these tiers, 8-11 km. Most torpedoes 4.5-8km range.)
Smoke
This brings me to their special. Destroyers can lay down a smoke screen to hide themselves and other ships from the enemy. It's essentially like a large placable bush from world of tanks. I haven't figured out the concealment details entirely yet, and there still seems to be a few bugs with it, but it does essentially seem to be much of the same. In the smoke, you're concealed until you fire, or extremely close, behind the smoke is total concealment. And smoke is VERY large. If you could coordinate it, your entire fleet could hide within a single smoke screen... although that might not be the smartest strategy, could be very surprising. The problem with smoke, however, is that someone has to place it. If you see smoke, you know a destroyer was recently there. Battleships avoid smoke, cruisers be very cautious around smoke. Destroyers can explore smoke at their own peril but might be better off just firing off a distracting salvo of torpedoes into the smoke or closing enough to spot for other ships to fire into the smoke.
tl;dr: Destroyers have extremely high damage output with their torpedoes, and can hide themselves and others with smoke, but are extremely fragile.
Cruisers - Medium Tanks, Sort Of
Remember where I said this wasn't a tank game? Well Cruisers are sort of like your medium tanks. They're relatively tough, can take a FEW hits, even several from other cruisers, and they're very versatile. They aren't as fast or maneuverable as destroyers, although some can be pretty zippy. They don't tend to have the torpedo output of destroyers(Americans only have two cruisers that have torpedoes at all.) But their guns can sometimes rival battleships for damage, and their firing speed is much more impressive. They can play a very effective attack role, seeking out the enemy and putting the hurt on them before speeding away to the next battle location, but their most effective role is probably as a screen for battleships and carriers.
Fleet Duty
Cruisers are the capital ships' only defense against the zippy little destroyers with their punishing torpedoes and the planes. Ah, thought I'd forgotten about planes nope. Cruisers have the rate of fire and accuracy to keep destroyers away from torpedo launching distance of Battleships and Carriers. Most cruisers have the AA ability to defend others against the airborne scourge. So a smart team will have a few cruisers hang back and keep themselves positioned between the battleships and the destroyers/planes. This isn't foolproof, planes can get through, destroyers can be sneaky, but it does help, a lot. This is definitely a much more teamwork intensive game than Tanks.
Patrol Duty
When you don't have a target to protect(rare, but it happens) then you're free to wander about looking for things to hit on. Almost anything is a valid target in a cruiser, although you might find that Battleships might be above your weight class and duking it out on even terms with another cruiser isn't the best use of your resources. Even if you win you'll likely be hurt badly. This is a game where strategy, teamwork, and tactics matter. Use your not insignificant speed and decent turning radius to sneak through the islands, get around and pound on something that's not paying attention for a bit, until they start paying attention then slip behind an island and get away. Just be careful you don't end up being one of those that get caught in that position. Most Cruisers don't respond well to attacks from multiple directions and despite their speed, nothing in this game moves fast except a torpedo. If you spend 30 seconds or a minute getting yourself into a situation, and you realize you're in trouble, it'll likely take you 30 second or a minute to get back out of it. While that might only be a single salvo from a battleship, that single salvo can hurt, another cruiser can put out a steady stream of fast flying metal in your direction and a destroyer can close distance fast and let off torpedoes in your escape route. Don't let this be you.
tl;dr: Medium tanks? Maybe. They can fill almost any role but excel at defense of bigger ships.
Battleships This is what we all came for, right?
Ah, the battleship. Ever since the days of placing little red and white pegs in a blue grid have we all wanted our own battleship to command. 16 inch guns! Armor thick enough to make even the Maus blush like it got caught in its underwear! That beauty! that style! Battleship.
The reality is a little less glamorous. And I have to admit, my experience here is very limited. I currently only have access to the very outdated(By most people's idea of "battleship") Kawachi class Japanese battleship at tier 3. It still should hold up relatively well in the basic concept discussion though. These are big tough brutes. They have big guns, they turn slowly and their guns turn even more slowly. Some are fast, fast enough to keep up with cruisers in a straight line in later tiers, but the Kawachi is a slow, lumbering beast. It doesn't even have all that great range. Some cruisers it goes up against can actually outrange it. Then why play it? Well, later battleships won't have that problem, and you still have the bulk and armor to stand a few hits closing in on the cruisers in order to show them what a real gun looks like. What'd you say? 8 inches? Okay... maybe not real guns yet, but someday. I've seen the Kongous in action though. Those are impressive beasts. They have the speed, they have the firepower. They are battleships. Only problem is that torpedoes can do a number on battleships. Kawachis can take a few, 3 maybe, before the ship gets damaged enough to worry about actually dying. I've seen Kongous take 4 or 5 and mostly shrug it off. To add to it, hitting even a battleship with a torpedo, much less 3 still isn't easy. This is still their weak point, and short of slugging it out with another battleship, or focused fire from a number of cruisers, this is how you handle them.
Guns
This is the most obvious feature of any battleship and it is what they do best. But they need to be aiming in the right direction. Big turrets turn EXTREMELY SLOW, usually slower than the turning rate of the battleship itself, so help yourself by maneuvering to aim and not trying to maneuver while firing. Firing rate is also extremely slow. Kawachi is over 30 seconds between shots. You can do several things to counteract this. First, make sure you hit. Nothing likes a full volley from a battleship. Second, fire slowly and with purpose. Click once, fire one gun. Click and hold, fire in sequence. Double-click, fire a full volley. Space out your firing, if you're not sure about the shots landing, this can ensure that you have a steady stream of shots moving at an enemy and they don't have a full 30 seconds or more in which to do what they please with you. They're powerful, but they're also inaccurate. Even on a target as big as another battleship, even under ideal conditions where you find a stationary target at medium range, a full volley of 8 or more shots can easily spread so that fewer than two actually hit. But when they do hit, they hurt.
More Guns
Cruisers have these too, they're called secondary armament and they can't be directly controlled by you, but they're there and when they're in range they'll fire automatically. (You can force them to focus fire on a target by ctrl-left clicking though, still needs to be in range.) On a battleship though, they're nothing to sneeze at. Around the same size as the primary armament on destroyers, can be as large as cruiser guns later on. These will pump out damage like nobody's business.... if you get in range. They fire autonomously, thus aren't connected to fire control like your main guns, and thus are MUCH less accurate. Still, let a cruiser get that close, they'll regret it. Destroyers, if they're that close, you're in trouble, but so are they. Two battleships, side by side, unloading broadside after broadside is a sight to see that everyone needs to experience once... but it's not tactically sound. Don't depend on these, but do remember they're there.
Even More G... oh, we're out of things to fire at for the moment? Okay... REPAIR CREWS!
Battleships have a special ability too. All ships have an emergency repair button. It puts out fires, it stops flooding, or repairs damaged engine, steering, or turrets, it does everything to get you back into the fight very quickly, but it does have a very long cool down before you can use it again. The battleship goes one better though. They can actually heal themselves somewhat. A limited use skill allows them to heal-over-time themselves somewhere around 10% at a time, up to 4 or 5 times, I believe. The heal is slow and it's severely cut by each hit you take during it so it's more for between battles rather than healing during battle. Still, with proper planning this can be a nasty surprise at the end of a game when a cruiser or two goes hunting for a previously heavily damaged battleship and the find one that has more HP than them combined still floating. But it takes time, and the cool down isn't insignificant between uses of it either.
tl;dr: In case you didn't figure it out, THIS is your arty. Gun range beyond sight range(later on, at least), slow turning, inaccurate, does best from behind a screen of other ships. Little chance if caught unawares by a destroyer. Play it carefully, play it safe, think ahead and pump out the damage.
Carriers Basically scumbags, right?
Everyone compares the carriers to arty in tanks. I admit they have SOME similarities, such as beyond sight range attacks, but the differences are just too numerous to allow that comparison to stand. At the same time, I've yet to unlock any carriers, so I talk only from experience of defending them as cruisers or trying (unsuccessfully) to catch them as destroyers. I've yet to be focus bombed or torpedoed by one, so I'm sure I'll grow to hate them more later, but for now. Carriers.
Planes
They have fighters, which fight other planes, bombers which bomb... things. And torpedo planes that... torpedo things. Fairly straight forward?
These are all limited in their numbers and can be shot down by both ships and aircraft. Once gone, the carrier is little more than a floating AA platform... if it even has that. History does have a few carriers that tried to mount main armament in the form of guns in front of, behind, or below the fight deck, so I'm curious to see if they'll make an appearance later on, perhaps in another nation's tree, but for now they're basically defenseless if found, except for their speed.
Speed: They do tend to be pretty zippy. I've yet to actually come close enough to attack one myself, even in destroyers, but that was more of an issue of planning and time limit than carriers just being "too fast". Although I could see the occasion where a carrier might be able to bring it to a draw by forcing the last enemies out of the cap and staying out of firing range themselves, I've yet to see that be a problem. Carriers DO tend to die in the games I've played.
tl;dr: I haven't played carriers, but there's little to complain about in my experience. They have their counter and they can deal damage, just like any other ship. I might come back to edit this once I've played them myself unless someone else throws in their experience.
Mechanics - They keep things moving
Okay, so now that you have an idea of what you'll be driving, here are a few basic mechanics that haven't been covered by the individual ship class descriptions.
Spotting
Obviously bigger things get spotted farther away, but unlike tanks, smaller things don't tend to have a better view range. These are LARGE distances over often obstructionless ocean. To see far you need a tall position to look from. This means that the big ships, cruisers and battleships will actually be able to see farther, most of the time than the destroyers. At the same time, battleships WILL be farther back so their effective sight range is lower than the cruisers, and sometimes the destroyers if they're playing sneaky flanky games. Smoke was covered under destroyers, but firing does tend to reveal your position. Outside of smoke, firing almost anywhere within line of sight will reveal you, even from your starting spawn position. I see a lot of people fire at the beginning of the game for no reason. DON'T. This just shows them where you are. Even if you aren't spotted directly, it's fairly easy to trace back to the general area of the origin of shots. Not necessarily good enough to guarantee a hit with guns, but definitely good enough for some blind fire torpedoes .
Terrain
Terrain is a completely different beast than in WoT. You have flat ocean and you have tall impassible islands. There's no in between on movement and there's very little in between as far as guns are concerned. Longer range ships can sometimes send shells over an island, but more often the island will just be a giant rock shield for you or enemies. They tend to be small and numerous. Plenty there to dart around and between, but each map is different.
Ammo
HE and AP make an appearance again, but this time the mechanics are completely different than in tanks. Over penetration is a thing, so using AP on destroyers is rarely a proper choice, while HE on a battleship can cause some damage to components and start fires, won't tend to sink it. There's also the difference between a side, or belt shot and a deck shot. Low angle shots will tend to hit the more armored side of the ship, high angle shots from a longer distance will hit the deck. Decks tend to be more lightly armored and thus allow better penetration and more damage by hitting interior areas. Angle off of bow of the enemy is important as well. Firing at the side of an enemy, especially with AP rounds limits what you can hit. A single component, and occasionally over penetrating and blowing right through with little damage a shot directly at the bow or stern though can cause the AP round to travel most of the length of the ship, hitting multiple components and causing massive damage. Damage itself varies wildly with some single shots doing only double digit damage(when HP amounts into the tens of thousands) and others completely destroying a ship with a single well placed "citadel shot" I.E. to the ammo or fuel storage.
So far, no gold ammo, but it wouldn't be unexpected if it made an appearance later. Also gun and torpedo ammo is unlimited except for reload time.
THE END? This is most of what I wanted to say, not all, but I got a call and had to leave in the middle, so I might be back to edit later. Any specific questions I'll try to answer in later posts.
tl;dr of it all? I find it a very fun game, good mechanics, very different from tanks. Things feel right, just the right amount of plodding along as ships to make strategy and tactics important while making things speedy enough to not become boring. A simulator this is not, just as Tanks or Warplanes is not, but it is fun, and I will be sticking around for the time being, as long as they don't do anything to screw it up royally.