War Thunder has been around for a while and has lots of content and lots to grind for. I have a specific interest in armored and aerial combat that only this game really fulfills to an extent and I would only recommend this game to people with a similar interest because if not, the way this game plays will not carry your experience. I entered this game interested mainly in World War II German tank technology as do many players who found their interest in various pieces of war media. If you're here because you want to fight in a Tiger tank, there are probably better games to get that experience.

With that disclaimer out of the way, War Thunder has a lot going on and it can be a lot to take in all at once so I'll explain the game the best I can and as simply as possible. A new player will start at 1.0 Battle Rating with Reserve vehicles: (at the time of review) ground vehicles, planes, patrol boats, and small naval ships. You are matchmade into games based on the highest Battle Rating of your lineup of vehicles. The Battle Rating or "BR" is the way the game rates a vehicle's combat effectiveness overall in the game. This tries to prevent unfair matchups like a M5A1 light tank having to fight a T-90 Main Battle Tank.

As stated, you will start at 1.0 BR and, by earning score in matches from damaging enemies and completing objectives, earn Research Points (RP) and Silver Lions (SL) in order to make progress on a new vehicle. For example: play well in your He 51 biplane and you can unlock a Bf 109 fighter plane. As you complete research on a vehicle, you then use Silver Lions (the currency that you earn freely by playing matches) to purchase the new vehicle. As you rise through the Battle Ratings vehicles will advance in technology.

There are also back end aspects of the game to be mindful of. These include the skill training of your crews, the costs of doing business (such as ammunition), and the cost of repairing your vehicles when they are damaged or destroyed. It's not as much as it sounds.
As you play, your crew will passively learn and allow you to spend crew XP to make your vehicle operators better at their jobs. New players will have new crews and each slot in your lineup has their own crew XP and vehicles they know how to use. Upgrading your crew skills can be things like Targeting where your Gunner will move the barrel both up and down AND left and right at the same time rather than in steps, allowing you to get the gun on target faster. When you purchase a new vehicle, not only do you spend your SL on the vehicle, you also pay a SL fee to train a crew to man the vehicle; so it matters which crew slot you train so you can form a lineup of vehicles for your matches.
After each match, you can check how much that match costed you in SL. When your vehicle is destroyed, you have to pay a SL fee to repair it otherwise you can wait for a set amount of real time for it to be repaired if you're hurting for SL. Keep in mind that the vehicles marked Reserve at 1.0 BR are free to repair so you'll never get blocked from playing the game. Many types of ammo also have costs to replenish. Often better types of ammo will cost a small fee to refill any used ammo, which you can also toggle off if you're hurting for SL.

Depending on the game mode you are playing, maps, vehicle performance, and other elements may change. In Arcade modes, vehicle handling is very game-like and you'll see where enemies are even through walls. Often Arcade maps are smaller and sometimes more exotic with objectives that can be wild. In Realistic modes, vehicle handling is more grounded while letting you operate in third person, game modes are usually territory control or target destruction, and the game no longer tells you where to aim. I recommend Realistic Battles. I don't have much experience with Simulator mode but it requires you to play in first person, with very little information displayed including teammates names, and there is friendly fire. This mode is a challenge and it pays better than other modes.

There are tons of maps with varying themes and locations. Vehicle eras aren't locked to certain maps, either, which takes away from immersion for me. You can fight in a modern city in your Tiger tank. From my earlier experiences, one of War Thunder's biggest negatives in my eyes is the map designs and how they are balanced. Often maps will have next to no protection for spawn areas. this leads to steamrolling and spawnkilling, especially at higher Battle Ratings where vehicles can engage from further away. Older maps that weren't designed with newer vehicles in mind still appear and maps that work well for World War II vehicles often don't work well with Main Battle Tanks from the 2000's era. You will experience this issue, likely often, and at the time of writing, it doesn't seem to be going away any time soon. All you can really do is learn to work around the poor map layouts.

Aside from that, there are also several premium vehicles for purchase with real money. These vehicles are often powerful or unique in some way and while many are just extras for enthusiasts, some are very powerful and common in battles. They are never required to be successful, of course, but you may face them more than you like, unfortunately.

War Thunder often hosts events that reward exclusive vehicles as rewards for grinding a long time during the event. These events also often have little game inside a game elements that, personally, seem to only exist to force players to spend more time on the game. Again, if you don't have an interest in war vehicles already, this game may not be worth your time because it often feels like it doesn't respect your time. Progressing in general can feel like it requires you to treat this game like a second job; which works for Youtubers but not for many of us that actually do work jobs.

I do like the gameplay, don't get me wrong. There's a lot here to experience and enjoy especially as you personally improve and learn how to succeed. I have 631 hours as of writing this to say that much and that's just what I've done on PC, nevermind the thousands of hours on Playstation 4. Yeah this game has crossplay and cross-progression (sort of).

If you do choose to try this game, go in patient, check the keybindings, and make sure not to frustrate yourself too much playing. This game is ROUGH and I've stopped play sessions many times from frustrating matches. It certainly helps to make friends and join groups. Good luck.