Hey, man! Glad to see you also made it on time to finish your OST. I found all the tracks very cohesive and great at setting a sombre but intriguing mood, perfect for that world you describe where a lonely robot is exploring empty abandoned spaces devoid of life but full of memories.
I would have difficulties deciding if my favorite is "The Aqueducts" or "Forgotten Chapel". In both of them the sound design and vibes are great, with that awesome "droplets" attacking sound in the first one, and the cool transition/drop around the 1 minute mark of the synth with delay. The sense of exploration created with the bass and the percussion also works very well. In Forgotten Chapel, the melodic apreggios entering at 0:30 are amazing and the mix with the background choirs, bass and the drums is also very well done.
Best of luck and see you around!