There is some potential here, but it needs some work. Especially in the controls and UI.
The mouse controls felt a little odd. Having to click on the tiles instead of the characters lead to a lot of misclicks and unintended actions. Being able to select characters by clicking on their models would be a big improvement, especially when trying to attack enemies.
Moving the camera with middle mouse button worked okay, but I think it would be better to use the right mouse button. It doesn't seem to be assigned to anything else at the moment. It's more natural and easier to do than holding down the scroll wheel.
The equipment UI felt strange to use. I had to click on attack options multiple times to select the correct one. I'm not sure if I was accidentally selecting and deselecting things. Perhaps making the button change colors or stick out/push in would help.
The Trooper's remaining AP is easy to miss. I didn't notice it until I was messing around with the equipment UI trying to select an attack option. Removing the movement icon next to it and just having "AP x[number]" would be preferable.
Line-of-sight for attacks seems a little off. I put a Trooper on a window, but couldn't attack the enemy standing slightly to the side. I'm not sure if I did something wrong or not, as characters could clearly shoot diagonally outside the house.
Enemies feel like they have way too much health. It took four 3-round bursts to down a single enemy; that's the entire turn of the Trooper. I stopped using single shots after I learned that. Adding enemy health bars would also be a welcome change.
Enemies teleporting around made it kind of difficult to keep track of their actions. I understand it's an early build and running animations are not done yet, but I would move it higher in the priority list. Even having them slide around would give the player a proper idea of what's happening.
Sounds were a little loud, and there seems to be a bug that causes the Trooper movement sound to get louder each time. It would appear to be playing the same sound several times at once. Otherwise, having different sound for different things was a very good idea and improved the experience a lot.
The low-poly art style looks good, but the fog-of-war needs some work. It wasn't always clear where I could see inside a house, and moving around only made it more confusing. Having noticeably darker tiles might work better than 3D blocks. The characters and enviroment itself looked fine.
Finally, I think there needs to be a visible enemy counter. Either it could be present at all times, or when there's 2 or 3 enemies left on the map. I walked around for a good 5 minutes, unsure if there was an enemy left alive or if I broke the game somehow. Eventually the last enemy walked into my full squad and paid the price, ending the mission.
With some more time and changes, this could be a nice turn-based tactics game!