My thoughts during gameplay:
First game: "Ok, let's find those orbs... Oh, can't go there... Nor there... Ah finally an orb! Wait what is that thing near the pillars? It's coming for me! Crap, I died..."
Second game: "Pickup first orb, check. Where is that monster? Nothing behind... This is weird, where did it go? Never mind let's go seek the second orb, but keep looking around for the monster... Second orb in the pillar and the monster is nowhere to be seen... Third and still no sign of the monster... Sneaky developers, they want me to be scared rest of the game but the demon won't appear anymore! HOLY SH**! Here it is again!"
I loved it!
Regarding improvements, most of what I saw has been said, but I will add that the walking sound should stop when walking perpendicular to a wall (I mean pressing forward button but not actually moving due to the wall)
Great job!