Hola! You asked for some feedback on melodic elements.
First, the good: I think your choice of instrumentation for your melodies was spot on. The doom-y piano and the hard synth works well and keeps the atmosphere all there.
Now, to improve: The piano sounds a bit obviously virtual. I think you mixed it decently well but here are two ways to improve the sound: 1) Actually perform or have someone perform those piano parts on MIDI. Or, if not that, work the velocity of the notes so that not every note is being hit with the exact same intensity. Since real pianists don't play like that, if you have a piano part that has perfect velocity, it'll always sound a bit fake. 2) Get a better piano vst (and still do step 1!). This is easier said than done, but if you're looking to upgrade I highly recommend VI Labs True Keys.
In terms of the synth melody, it's not bad. It just didn't strike me in any particular way. It's very good at adding to the atmosphere, but it didn't strike me as catchy or memorable. My other issue with it was that once had begun, it maintained basically at the same level for the rest of the track. You pump it up the octave at 1:32 but it's still essentially the same thing. So a little more variety in the melody would have been nice.
Hope this helps!