Nice Trailer
I hope my comment will not be judged negative, that's not the intention.
The art was very good, on its own way.
There are some questions that came to my mind when i watched the trailer.
1. If he is infected and travels to the past, didn't he infect other people from the past too?
2. Why doesn't he know of the virus, if he holds a test-tube in his hand, is he a scientist?
The story is interesting, at first i thought it will be another zombie themed game, but then the time travel made it more interesting.
I just want to give a small hint. If you are planing to add time travel, where you can switch between timelines, then please make it very logical, otherwise people start to turn away from the game.
(Time Hollow is one example, at the end the time-travel device was passed from protagonist to the same protagonist and no origin of this device was mentioned , so i was a bit disappointed of this paradox.)
You should definitively add some more information or informative pictures (not too much for sure) to the trailer, cause it would match if you can see the "love" or some screens from the life of the protagonist before the accident with the virus takes place.
These are only my opinions.
Good luck with your project :)