Rather than having a trusty computer and internet connection to look up people and places, Lauren instead has a phone book and landline phone. This means that you often end up briefly heading to your apartment just to turn a name into a phone number or location so that you can head on to the next location. I like how the reliance of these everyday tools means that we can venture into a large variety of locations without either Lauren or Joey have a mysteriously complete knowledge of location geography, people and businesses.
Lauren and Joey also have a very different relationship than Rosa did, Lauren clearly has accepted her role as a medium and that Joey isn't going away. They have a reasonably good working relationship and they banter a bit more.
The game has a hidden timer to it. Lauren is a chain smoker and there are 2 achievements that are possible, one which is to finish the game before she finishes 20 cigarettes and one for finishing the game with Lauren smoking at least 100 cigarettes. It is an interesting idea and one designed to get people to play through it multiple times. I kind of liked how you got some of these meaningless statistics when you finish the game.
One thing I do not like about the achievements for the various Blackwell games is that Dave Gilbert really seems to like achievements for solving a puzzle without making any mistakes. I find this really annoying especially since it is possibly to encounter these puzzles well before you have the information to solve them, before you really even know that it is a puzzle. It basically means that they are a set of achievements that can be gained either by playing through the game twice or to just use a guide to finish the game. Adventure games already have a significant problem relating to guides, they don't need to give players more incentives in that area.
Blackwell Unbound is a good prequel and it sets up the events of Blackwell Convergence, it took me about 2 hours to finish it.