To preface; Vietnam war is easily Thor's most ambitious game, the scale of the game is massive. Though the content is more shallow than a puddle.

As an early tester, I can tell you that Thor put a lot of passion into the game, the details are great, flying controls are good, but the ground combat is lacking.
The infantry combat mostly consistent of getting shot at AI that can see you through terrain and trees.
Currently the only objective as infantry is to capture bases or defend them, which will end up being tedious due to how the AI is. AI will always fire rocket launchers at you if they have one (even in close range), vehicles will snap onto you, and for the funniest one, AI will bayonet charge you like it's the 1800s if you get too close.
The air combat is where the game shines the most, but I don't have much time with it to fairly review it.
To end of this section I'll just quickly note some issues with the AI;
Snapping onto the player even when there's friendly NPCs nearby, tanks auto lock on the player constantly following them with the turret, occasionally they run into solid objects when bayonet charging, and AI use RPGs against infantry at like 50m (tbf I can understand this one as a Squad player x3).

The details in Vietnam are where Vietnam shines. Thor put a lot of effort into it and it is obvious.
Several ground vehicles have very detailed interiors that are functional, bases have functional props like armouries and workbenches. Etc.
One detail I will complain about is NVA using US rank emblems & US army/marine pilots using Air Force rank emblems.
The graphics are also alright, but since this is not a mobile game and I'm not writing this review on TapTap I'll leave it there x3.

Honestly, this section is the main reason I'm going to be marking the game as not recommended.
Firstly the optimization. Myself, I have a decent PC (CPU 5700g, GPU RX 7600, and 16gb ram) and the game "runs," I have played UE5 games with better performance. The game runs at 75 for me until it does not, tabbing out of the game can cause a permanent impact of 30-40 frames, once any fighting starts the game will drop to like 35 frames and stay there, etc. there might not even be much going on and it will just tank down to 10fps on it's own.
Bugs... The game is a mess, there are bugs everywhere.
To name a few I've found from game breaking to funny to give an example;
Game crashes when trying to access a planes equipment load, game crashes when changing sub faction, broken terrain causing NVA bases to float, guns/vehicle interiors shake, ai bend to shoot up and downwards, rifle scopes aren't designed for PC resolution (the box goes off screen and the scope isn't centered), and finally, civilian vehicles just disappearing on bridges.

Overall, I can't really recommend the game in its current state. The gameplay is shallow, the optimization is poor, and it's full of bugs.
If thor fixes the issues listed here in the future I'll update my review, as the game can be quite fun. It's just not in a good state right now.

Edit 1: Steam formatting 1, this stupid wolf, 0

I really wish i could recommend this. The concept is awesome, the sheer scale and detail of the map is insane. so many weapons and vehicles and things just constantly happening around you is super cool. bombing runs, planes getting shot down random firefights etc. the vehicles are amazingly detailed and rendered. though. Flying and responding to calls for help is so much fun to me as well. that where most the good ends. the moment is so floaty and just painfully awkward. crashes are incredibly common and frustrating. the lack of direction and lack of a tutorial is also a no go. the sound design is just terrible and lifeless. The reloading sounds are just straight up awful, like nails on a chalkboard. the 14.99 price tag for this game is nowhere close to where it should be. I'm not hating, the game is really interesting. This game could be GREAT. The potential is absolutely huge. But there is so much work to be done. I will be watching closely for updates. but nonetheless i unfortunately cannot say you should spend what is asked from this game. I do understand that it is a one man developer team. but this product is not finished and needs a lot of work.

Its nice, need anti alasing, little bit of optimisation, for now its pretty good sandbox