Slow but unsavory pace and inadequate characterizations. These plus the premise don't do enough to justify the show's 8 episode length. You don't believe the people are real, which makes it hard to take the sci-fi implications seriously. Add to that some plot conveniences that are trite or even "magical". An example of a sci-fi show that succeeds where this show falters would be Steins;Gate. Slow-paced shows that are yet more savory would be Twin Peaks Returns and Too Old to Die Young (excepting the last few episodes, perhaps).