Update: With almost 500 hours in this game, I can say that it is still a blast to play!

Original:
After spending close to 140 hours in this game at the time of writing this review, I have basically seen most of what the game has to offer and I am enjoying my time with the game quite a bit.

It is a great mix of 6 vs 6 multiplayer matches with the default game modes and a Rogue-Lite PvE Expedition mode. The multiplayer feels like a mixture of a more old school Call of Duty with some heroes and abilities/ultimates thrown in, which results in chaotic, yet highly enjoyable gameplay. Most of the gamemodes are fast respawn modes like Team Deathmatch, Conquest or Escort. Domolition is more of a Valorant/CSGO bomb mode playstyle without respawns, only revives.

The biggest issue with the PvP content is, that Escort is currently limited to one single map, which gets very boring after a short while, Similarly the amount of maps for the other modes is also sort of limited. The saving factor is the rotation special events, that switch every few days, where the developers test new modes, new maps and sometimes event story missions.

Edit: Maps and content has been added over time, but currently it is stalling due to the continued attacks on infrastructure in Ukraine.

The expedition mode is something really interesting. It drops you off on a map with 2 more players and then lets you run from boss encounter to boss encounter. At every step to the 4th and final boss, the game allows you to extract after every previous boss and take your earning with you, tho most players opt to continue playing, if you are playing with random players. Between the bosses you come across obvious or hidden loot drops, that either drop you guns or your characters abilities or special upgrades that are exclusive to this mode. You can always opt to search for more drops, but that also means, that the contamination counter increases over time. It has multiple steps and once it fills up, a random downside is activated, which could be enemy shields, air strikes or other things bothering you for the rest of the round.

The Expedition is pretty fun, especially due to the amount of randomization, that can happen through the boss encounters, the route taken by the players and the upgrades chosen. You can never rely on your most favorite gun and often have to chose between a life saving ability (med packs) or a better gun or opting to reduce the current contamination level for the team. The downside is, that there is only one map, which is pretty big and varied, but in the end it is still one map.

If the biggest flaw of a game is the lack of content, while it is in Early Access, then the developers are doing something great. They definitely need to expand their content, especially for Expeditions and Escort PvP.
Another downside is the netcode or how the game handles PING, server locations and everything connected to hit registrations. It never feels quite right: From the game starting with pre-selected Asian servers in Europe, of the fact, that every gunfight has some sort of laggy jank to it, just feels off. With some patches and improvements, probably an increase in tickrates for the servers, would make this a ton better. Don't get me wrong, it is not bad, just not as good as it should be.

I have read a ton of reviews talking about obvious cheaters and while I have seen some shady players, I only rarely saw players, that could have been using 3rd party software. Maybe the European servers are less affected or I am just lucky, not sure - I can only talk about my own experience.

Regarding the monetization: I bought the Battle Pass for 10€ and completed it, which gave me more coins than I invested, around 13€ worth. Other than that, you can currently only bug a support trinket, rail decoration and some character skins, which are geared towards big supporters, because everything else is just in the battle pass directly.
While it seems like the Battle Pass is purely cosmetic, and for a large chunk it is, it definitely boosts your amount of silver coins you get, which helps you unlock new guns and attachment slots, which can be a chore, if you intend to use more weapons. By the way, the game contains loot boxes, but they are just part of the operator tasks/weekly tasks and the battle pass and not directly purchase-able.
In my personal opinion, the current monetization seems absolutely fair, but as it is an Early Access title, it could always change for the better or worse. I would recommend everybody to see the Battle Pass as an entrance fee, if you are interested in playing the game more than just a bit.

Edit: There now were multiple premium skins roughly worth 10€, which look pretty nice. I actually spent the money on them, but more to support the developers than just to get the skins.

About Progression: The key to progress in this game is completing Tasks. Daily Tasks, Weekly Tasks and Special Event Tasks. There are so many Tasks to play and most of them never expire, so you get as much time as you need. These tasks give you XP for the Battle Pass free or paid and silver coins for guns and attachments, as well as Blueprints. If you have 300 of them you can craft a random modification of a gun, that has a special trait and a special skin.
Most of the rest of the game is just playing the game. Leveling up a gun means using the gun, both in PvE and PvP. Getting new weapons (a higher tier), means earning more XP (I reached 4 out of 5 tears in 70 hours). As long as the core gameplay loop keeps you in the game, you will always progress in some way.
Luckily, the first tier of guns is free and the characters themselves are also unlocked from the beginning. Their abilities get stronger from Level 1 up to level 8, which you can upgrade by playing the character. There is no real way to speed this up with money.

Edit: Weapon Tier progression has been updated and I instantly jumped to having all weapons unlocked for buying with ingame currency.

It is too early to say, where this game will go, but I already had a ton of fun with this and continue to look forward what the developers have to offer. Their rotation of new maps and modes is definitely a nice way to keep player interest and trying new things without throwing them in forever, but only after feedback has been gathered.

The game is free, so try it out, play a few rounds and give it some time to shine, because it may need a few rounds, before the whole thing comes together. Thanks for reading and I hope you have an awesome day!