So first impressions. Really cool UI, the menu and little intro sequence looks great (love the menu animations in particular).
Would like an option to be able to skip through the opening intro by clicking though, as it's a little annoying having to sit through it all again on second playthroughs.
In-game visuals are nice. I know you said some of these were from asset packs, but it's good that you managed to get things that complimented one another. Nothing feels weirdly out of place, and it all matches the soviet industrial theme you were going for. The mechs look great and are definitely the highlight of the visuals.
Audios a bit of a mixed bag, some stuff sounds great, other things like the out of breath sound effects are a little... off-putting.
As for the gameplay itself, I gotta admit that I couldn't beat it. Hell, I could barely activate more than one of the button. Enemies seem to spot me through obstacles and would often ignore the flashlight when I shone it at them. Because buttons tended to be in a container or against a wall, the enemy would end up trapping me with its collider and beat me to death in the corner.
Your stamina and battery life for the flashlight are also very low and there's no UI elements to indicate how much you have left, which meant I would end up in situations that I was unprepared for.
I think if you fix the enemy detection and stun effects, and increase the amounts of stamina and battery, it will make for a much smoother experience.
The good news is these problems are things that can be fixed with some tweaking. The core gameplay of this is fine, and I think it will turn out great with some adjustment.
So well done!