why is the game no longer on steam

I'm at the very beginning. I find two in paintings but I can't seem to find a third. There is an arrow on the wall that seems to point to nothing. I tried watching a guide for help but the player was able to take something from a lamp and I cannot interact with those. Is that related?...

Can someone enlighten me on how to use inventory items? I hit the "I" key and inventory appears but I do not know which which key enables its use. Mouse just roams around room without staying on the object in which to use the inventory item. Thank you

-I'm curious on what the numbers means on the ceiling at the start. -I cant interact with all of the items for the achievement -I'm not sure what to do with the pentagrams on the floors. I tried killing the spiders while they're on it and also the mannequin but it doesn't do anything. -When you go to the second floor and go back to the first where the mannequin and safe is at you get an extra key for interacting with them again but the keys do nothing. plz help i need to 100% this game...

I watched the ending credits after finishing the game a few times and from the menu but couldn't get it. And also searched every possible item, including the 3 scrolls. But since the game has a random element and items can spawn in different objects every playthrough, do I need to keep replaying it until all items placed in the game are searchable? Thanks....