In the beginning the plot had me interested to see what would happen next. Towards the middle things became drawn out and predictable. Towards the end much of had been built up to that point was meaningless.
Spoilers: The nail in the coffin for me was that Vanya was sorry for what she had done in the end, and, being the otherwise grounded/well-adjusted character, her reflection starts talking to her and convinces her to do a 180 and just be super destructive. This was out of nowhere and reeks of some manager saying "But we need to have a climactic ending!!!"
In the end, a lot of the plot didn't matter and it feels like all of season 1 was made to promote season 2. I regret wasting my time and I won't be watching season 2.