I got here from DuckTheAugust's gameplay video. Anyways, this is a decent and fun demo, but I'd like to point the flaws out first, since I think they pale in comparison to the good qualities.
Warning! Spoilers for the demo below!
I do not like the fact that there's no control menu, and instead the game opts to show you the controls at the start of the game. Each individual control takes too long in my opinion to proceed to the next one. Why not just add a controls menu, where players can read each control at whatever speed they want? Another flaw, I guess, is the fact that the ambience of the building is relaxing, not at least creepy. This is a horror game, and while relaxation is a pleasant feeling, horror games are not meant to relax the player, unless if they're providing a break from the horror, which the part of the game with the ambience playing is not. Another thing is the fact that the characters giving you stuff do not have an animation for that; the thing they give you just pops out of nowhere. The 4th one is the fact that when Sadman dies, he just dies out of nowhere. There's no clue why he was murdered, 5th, during the fetch quests, there should be more obstacles in the player's way before they can give a character what they want, 6th, there should be more secrets, like for example, I'll suggest you to make it so that you can break bathroom stall doors with the cereal gun, and if you break the one with the guy behind, he'll just stare at you forever, and also, you can break other things in the building with the gun, 7th, there's no pause or options menu, and 8th, the hurt sound sounds too goofy.
Okay, now to the good qualities. 1st, the puzzles are pretty fun to solve. 2nd, I like how there are enemies in the building that I can defeat, 3rd, when hiding in the chest after the alarm goes off, when Fred goes near the chest, it can cause you to get scared that he'll catch you, 4th, the game's pretty funny, ("Mha ha ha ha ha ha ha ha!" "Come to me!") 5th, the enemies look creepy, 6th, operating the cereal gun is pretty fun. You can even destroy doors with it! 7th, I like how walking on blood makes a gross sound; I like that detail, and 8th, the warehouse minigame is pretty fun and challenging.
Hopefully dev, you read the whole article, and you can fix the bad qualities listed above, and amplify the good qualities also listed above.