What program to use to make a game and design characters like Cube World/Minecraft?

I would like to try and make a game like Cube World/Minecraft and to design characters like them. Is there any good programs to use for them please?

Firstly you want to start and download a game creator software and start learning to program games before you make a big game like minecraft. It might look like all you have to do is put in some pretty pictures and bobs your uncle but its not that easy alot of effort goes into making games but once you get the hang of it youll be unstoppable

UDK/Unity
Both free.