Title: The use of the cello as your melody instrument over a gentle high piano line is an interesting choice, but to me gives a sense of immensity of the clock tower, while at the same time giving a sense of calm that for the time being we are safe. I like the soft wood block helping to keep time in the background. I wonder if a “bigger” sounding instrument might help give the impression that the game takes place in a clock tower with much larger structures? I still think it works well with the intended effect as is!
Puzzle: The polyrhythms in the different layers give a sense of mind-disorganization that works great for a puzzle level. The initial minor progression adds mystery to the piece, which the piano comes in to try to solve and helps add clarity to the puzzle.
Safe Room: As the piano gets louder, especially in the lower register, I am beginning to wonder how safe this safe room actually is! This is some beautiful and haunting piano work - good job!
Battle: The 5/4 strings are really cool and make this my favorite out of your OST! I also like that the wood blocks follow the 5/4 time making it feel like time is skipping and is not moving the way it normally should.
Game Over: This duet is a somber piece that is perfect for the ending of a game, though holding out the last notes a little longer may work well to add more of a sense of conclusion to the end of your OST. Or maybe it is intended to repeat at that point?
Overall: This OST transports me to the eerie clock tower location that you set and definitely would add some emotion and suspense to the puzzle game you describe. Good work and thank you for sharing!