Open Question: i have a question about game design?

i am looking for a program that is not to hard to use to create a computer game. i want to design a first person game. i want to make it very realistic, like ragdoll people when they die. and a inventory where you can pick up swords, daggers, bow, arrows, armor, and clothes. i want to design a sandbox game where you can explore. i want wild animals like wolves and deer in the wilderness, etc. what is the best program to use to design a game like i described?