I listened to all your three demos, and I'd say you're pretty good at it! (And I genuinely mean it.)
These are the stuff I'd like to suggest to make these tracks improve. These are just my personal thoughts, btw.
1. Chord Progression & Theme
I overall enjoyed the chord progression and the instrument choices for the two previous tracks. It gave a nice horror-feel inside it, and I liked it. After I listened to these two tracks, I was getting ready to say that you should challenge in different themes as well, until I came to this third one. I liked how you tried to create with another tune, but there was something I had to point out. The notes from the instrument are unfit to each other in some chords, despite the beautiful atmosphere you created for the song. This could be unpleasant to some people who prefer perfect harmonies like me.
2. Production
This is also for the third track. I'd suggest having more sustain pedal on the piano. It sounds too sharp for a soft song, especially on the higher notes. For me, I have this same problem while creating cinematics with my phone — the piano (and all the rest of the instruments) sounds too robotic. So I give substantial technical adjustments to the instrument itself, adding more reverb, sustain, and EQ tweaks.
I think this is it for me, I liked your tracks overall. You have some talent. I look forward to your future cinematic scores. (And longer, please!)