"Let's make a mediocre turn-based tactics game and slap the ArmA brand on it!"
That's the game in a nutshell. It has nothing to do with ArmA and it doesn't even remotely offer the depth of an ArmA game.
The gameplay mechanics are pretty similiar to the new XCOM. Everyone of your soldiers has two actions per turn. You can move, shoot or use an item, reload your weapon, etc.. You can, of course, use both your actions to move further or take an aimed shot, too.
Just like XCOM, it also relies heavy on the use of cover and just like in XCOM there is also high and low cover, high cover of course providing more protection.
You also don't need to worry about ammo, as you have unlimited, but you need to reload, when you've emptied your weapons.
Items like grenades or explosives have to be bought before a mission from the armory. You can also upgrade your weapons or buy new ones, but be aware that you can only use one weapon at a time. There are only four weapons, btw: an assault rifle, a LMG, a sniper rifle and a shotgun. There are also no sidearms. You do have a knife though, which you can use in close combat.
Your team always consists of the same four people. If anyone dies, it's game over and you can restart the mission. None of them is able to climb even the smallest obstacle. If you can't reach a place by walking, you won't get there.
Oh, and if you decide to restart a mission, you lose the items you have used. Yes, whatever you have used, be it grenades, medkits or something else, are gone and you need to buy them again, which is utter stupid. If you restart a mission you should get the gear, with which you've started the mission, back.
Now let's talk about the AI, shall we? They are incredibly stupid. They love to run out of cover and right at you. Quite often they even shoot with their first action and THEN come closer to you. I've also witnessed them running into cover with their first action and with their second action they ran out of cover again...
Also more than once the AI wouldn't react to getting shot. They'd just stand there, doing nothing. They also seem to be deaf as they often don't react to gunshots, even if they should be in hearing range.
And the game seems to be quite buggy, too. On one mission I was teleported to the objective, while it was the enemy's turn, which pretty much broke the game, so I had to load the last save, which didn't help, because the game teleported me AGAIN. It did that also a third time, although that time it was actually my turn, which didn't help me much, because I was surrounded by enemies.
Another time I healed a character from across the level. And another time one of my grenades landed UNDER the floor, where it exploded and did nothing. And while we're at grenades: it seems sometimes you can't throw them over cover for no apparent reason.
I'm not going much into the graphics, as the game is a mobile port, but it looks bad. It's pretty much the same with the sound design. The voice acting is pretty bad and the subtitles often don't match what they're actually saying.
The camera is also quite bad.
All in all, this is a really bad game. If you really want a TBT game, you're MUCH better off with XCOM. And if you want the, imo, best in the genre, get Jagged Alliance 2. Combined with patch 1.13 this is by far the best TBT game you can get, even though it doesn't look like much nowadays.