Generally speaking, you aren't required to play Terminus Reach: Sentinel first, it helps with some of the references and relationships, but the story itself is "stand-alone" and doesn't need the first one to be played to make sense.
Am I imagining things or has Lindsey had an upgrade to her character model?
She looks great.
Okay so. About the models...
The majority of the models are still the same, mostly, but there have been texture updates here and there along with some changes to the bodies.
Chiel: had her skin changed to be more modern than freebie Genesis 3 skin, which wasn't bad, but it was a bit outdated. Tried to match it as close as possible to the original. And I had to do a custom morph for her to fix an issue with the mesh, namely the eyes being... weird.
Lindsey: her skin and hair changed, the skin was made by the same person as the original, just for Genesis 8 and paler. And outside the whole pregnancy, she had few body shape updates.
Sage: Stays mostly the same, a bit more bustier and different hair.
Nova: Pretty much identical to what she was in TRS1 as she had the most modern skin I had available at the time (Zelara 8).
Aegis: Her body got a bit softer from TRS1 otherwise the same.
Qivian: She didn't have any changes really.
Zae'na: Had a slight change to her body, something that I wanted to do in TRS1 but wanted to keep it consistent within the game so didn't change it then, Ne'quk uses the same body, just shorter and slightly different facial structure.
Andi: Had her hair changed and I think that was it for her.
That's from the top of my head. There are some new characters popping up but it's majorly the "old crew" at the start for fairly obvious reasons. And now a bit more generally about the graphics.
And the biggest reason why things might look better is that I don't have to reduce the textures anymore unless I cram 10+ people in the scene, but if they are on the screen same time they aren't close enough for the texture size to matter. That and I actually have some clue what I'm doing now when I light the scenes. And no, I still don't care for going "realistic" so the graphics tend to look a bit outdated, this is more or less an intentional choice on my part.
The only thing I think could be added is a list of characters and location. Even something like what Sorcerer had with just a list wouldn't be bad, or you could go like Tales from the Unending Void or Mass Effect and have a full-on codex with pictures and stuff. Wouldn't need to be voiced like Mass Effect's of course. Not really needed but it would be helpful when so many names of people, species, and location get tossed around.
There is something in the works, but it will take a while to be sorted out and look like what I want. Can't say it will come fast as I have a lot to sort out still... but it's on the back burner simmering.
This will be a nice surprise if it isn't a joke. :s
No joke, TRS2 is under production, update 3 is underway already.
EDIT: added stuff.