As someone who thoroughly enjoyed the visual novel, the anime was definitely a letdown for me. I still enjoyed it, don't get me wrong, but I feel like compared to the visual novel it just isn't as good. The animation is pretty bad at times (looking at episode 3) but it isn't the worst. The characters, I feel, are pretty well established and their backstories are explained smooth enough. The way they were able to fit in each character's backstory despite only choosing the true ending (Ren's ending) to base the story on is very well done. The music is probably my favorite part of this anime, which is nice considering the original had very good music as well. The voice acting was fine (not counting the dub), and it's certainly a big comfort anime for me personally. Overall, I'd recommend playing the visual novel first if you are into BL and THEN come back to watch the anime if you enjoy the visual novel enough to do so!