Going to be honest, this movie bored the life out of me. The pacing is SO slow. The characters are SO flat. The only bright spot was Puck, but we don't get enough of him. Despite that, everything surrounding him carried me through the movie. The villains sucked in a series with fantastic villains. Just really does not fit in with the quality of the rest of the series. Really did want to like this, since it was supposed to be Emilia's backstory. By the end of the movie, though, I just could not care less about her motivations and the whole climax. Never seen pacing kill my enjoyment of something like it did for this. Such a shame. Really should have been some bonus OVA or something that was maybe half an hour.
Still glad I watched this as a massive Re Zero fan since it does enrich the world somewhat. Thought the monsters were pretty interesting and seeing how the characters ended up where they are in the show was nice. Don't really know about rewatching it, since it's a slog, but at least there are some cool things you can get out of it (no pun intended).