The idea is cool, lowpoly visual style is good here, particularly liked the idea to put glass shards and such on the floor so it makes unexpected sounds when you step on it, this supernatural demonic setting is interesting one too. But overall its still alpha and has some issues, like weird sound positioning most of the time in the missions, stupid flashlight that won't obey you and works really bad when you are close to something, other two S.I.N guys felt kinda useless to me, because demon are not that dangerous actually, some weapons like water gun and cross are weird, demonic trap is interesting, but never have a chance to use it. Shotgun and a rifle solve all the problems here. Also purpose of skeleton vision is not really clear to me, it shows you demons right away so you know who is the danger, but i thought the whole point of the game is shouting at everyone, guessing if they are possesed and gonna lunge at you with that butter knife or just a dumbass that you don't really wanna kill, then deducing who is the demon or not by some signs, setting traps maybe etc. Skeleton vision kinda ruins it all, but even then, you know who is possesed - you shoot them with non-lethal gun - you got penalty for non-authorized weapon use?? Mister i can clearly see they have evil within them... Maybe vision should be an upgrade or something like this, or have significant cost, or completely removed and replaced with another system for recognizing demons, think about it. 
Movement feels werid too, maybe it is that arms animation not synced with the movement speed? Maybe character should be a little bit faster, or animation should be corrected, its hard to tell. And also this game has a lot of typos, almost in every sentence, even the game title in the main menu, it doesn't spoil the entire experience, but ruins the mood of the game? Like it feels not that serious? So i think it is a good idea to read everything a few more times or maybe use some text editors to spot mistakes early. And i think the loading screen could be improved too, the first thing you see is "Made with Unity" and it feels cheap, maybe the dev logo that comes after or the game title should pop up first. Font for texts i think could be improved as well, currently it doesn't really fit the atmosphere of the game. All things aside, the experience was kinda fun, would like to see where this game gets after some time. Genuinely want you to learn and improve and make better stuff, so that is why i spent time (maybe a little too much) recalling all the little things that i wanted to tell about! Sorry if there are some alien sentences, english is not my first language. Best wishes to the dev, keep going!