This is one of my go to adventures for players just getting into 5e. It has a great mix of RP and combat, some story rewards for doing bad things and a ton of interesting story points. Much like most adventures, the RP is up front and the combat is in the second half after exploring the depths of the keep itself (mostly the Jade Temple). The spirit is a nice touch as well and helps explain away any other way the adventurers try to light the lighthouse again. Supernatural beings make this super easy.
The exploration of the keep is fun and fast paced. Easy to understand and you can really picture what's in most room through the descriptions while leaving plenty of room for custom elements to be added.
[5 of 5 Stars!]