A good balance of chance and repeatability --- strategy with guesswork. You get semi-random cards to choose from and manage your deck. So there's always a potential different approach, provided the stars align in another manner. You also discover new cards, that can be received, for future runs. Together with RPG-like elements, this makes for a good sense of progression. The main 'line' is built to be played repeatedly, with more restrictions and stronger cards to be found.
I thoroughly enjoyed the, as Dave Gilbert puts it, mid-era Bioware kind of storytelling. Taking a mix of characters on missions makes the world feel deep because the solutions depended on their particular abilities. It is apparent that had I chosen another party member, the solution would have had to be different. The writing is up there on the high Wadjet Eye bar, and together with the flexibility and alternative origin stories, makes the world feel deep and reactive. I enjoyed the narrative, the pacing, and how <spoilers> worked out in a creative way I hadn't expected. The party banter is great and organic, the dialogues feel natural and do a good job at seemlesly incorporating the origin story of choice into them. The choices were hard to make and it was interesting to hear party members reflect on what the protagonist had done. I appreciate there wasn't one option that seemed most correct (looking at 90's RPGs where the longest dialogue option was usually right). Altogether, I got really personally involved as I played and I consider Unavowed one of my all-time favorite games.