I was Reincarnated Into a Fantasy world but i have a Game Menu system?

A young man who is a workaholic and also a engineer gets into a tragic accident after saving a kid and walks towards the light. instead of peace, he finds himself im a cage surrounded by weird looking creatures and other woeful people in the cage. He then finds a Popup that only he can see... Join the man on his new life in this World.

P.S. This is a really simple Light novel ive written for practice. dont expect it to be any good since its not really planned, im just writing whatever enters my head