The fun part about making music is the experimental part of discovering new sounds to work with. I think this is good if you're into horror or thrillers, it's something that captures some grotesque scenery. So here's what I think of this piece:
Let's start with the pros. Well I like the beginning of this. I see what you did there. You tried to capture the heartbeat type of beat lol. This is nice and it gives some secondary character-ism to the song. It definitely has a level of creepy in the background and wouldn't mind listening to this on a video game. It's perfect for a horror game in many ways. The style, the beat, the chill that runs down your spine. Qualities music needs to bring to peoples attention.
I find it awesome that you tried to synchronize the piano roles to each section of the song. Pianos are just a great way to add some atmosphere for just about anything and this one worked out for you.
With every good there's a bad:
So everything seems just fine but as I listen it feels dry. The song has some good atmosphere but what makes horror grab you by the heart is the effects. Reverb, Delays, Sustains, and LFO effects can really help out with bringing the atmosphere to life. I can give you an example of this in one of my songs "City Ruins". It amounts with lots of reverb and sustain which when pairing with keyboards, pads, and atmospheres it can easily bring out that tense but bassy reflections of sub bass that sends chills down your spine.
Other than that I'd say mixing and mastering too but that's problematic for everyone even myself. I definitely think this has more potential and if you were to take my advice and try to add some reverb and sustain it will help you clear a path for a smoother transition in atmosphere. With the right tweaks this can be movie material sound. I enjoyed it.