I've played the game for a bit (finished the mines) and these are my thoughts:
The concept of the game is very interesting! I had a good time playing it. The levels generally have nice solutions that are fun to figure out. So gameplay wise, this is great :)
The main thing that occurs to me is that the game needs more polish. The screens that show when you run out of time or trigger a paradox seem out of place. The watch showing the time is very cool, but the art style clashes a bit with the style of the game I think.
I found the background music a bit annoying and just turned it off after a bit.
Overall, a good experience. Not sure if you are still updating this, but would love to see it be improved even more!