I don’t think it was awful. It was not sensational either. I have not seen the whole theatre show myself; just individual songs. However, there are lots of fans of the original therefore there was a lots of potential hence possibly people’s disappointment. If it was an original picture perhaps it would not have been criticised as much.
It was watchable. I do think visually it was quite dark; with the brown cats against background of London at night. London could have been made more twinkly lights to showcase the cats. With musicals like Greatest Showman and La La Land in recent years we have probably grown to want more than just watchable.
In conclusion, not one to rush to see but if you fancy it give it a go, it will keep you reasonably entertained.