I'm playing Nier Replicant now. I've played the original on PS3 and it feels weird that the protagonist changed from a large, grumpy dad to a small sweet child taking care of his sister.
Completely changing the protagonist in the original release is such a weird choice. And had to have been so much extra work.
The change was done to appeal to western audiences who they said would like a gruff older man better, so it was only dialogue changes that were done all over to account for this. The story is otherwise the same. But yes the character dynamics change a lot when the hero goes from like a 15 year old to someone around 40.
I only just met Kaine, but she's a companion who is around 20 years old, which obviously makes a big difference whether she'll palling around with a teen or a much older man. I look forward to seeing how the writing her changes.
The original Deus Ex changed how I saw story telling in video games. Now says it's not that ground breaking but when it first came out it changed everything.
I had a similar experience with Deus Ex Human Revolution :) I got sucked into the world and now I plan to play all the entries (and started the oldest one).