This game has a lot of potential but there's some things holding it back.
There's loads of backtracking with keys that you can't judge which door they're to be used on so you gotta try every door until you find one that opens, and for each door you have to open the inventory to use the key, it got quite tedious after a while. A simple colored key and lock system would have done wonders here. Or if you wanna go the extra mile, a themed key set like in resident evil ("This lock has a diamond on it" etc.)
That first enemy is pretty much guaranteed to kill you at least once (and because it was so dark I couldn't even see where I was going so I died again even after knowing how to avoid it,) and it's frustrating that it's a bit away from the save spot.
I assume the controls are all as they are deliberately but I didn't really like the mouse turning, or the inventory having to be constantly opened for even the map.