He actually did compose for both AOWD and EON, for EON some tracks are done by his musician friends from a local band if I'm not mistaken. Coding wise, he does some heavy scripting, but game engine is Visionaire Studio, specialized in adventure style game development. Writing for EON is done by him and his female friend (an amateur writer).
At first glance it may seem unbelievable, how can one man do all these! But the dev is one of a kind, talented, ambitious and extremely hard working, Swiss Knife kinda dude.