domain name vs ip address?

i get that a domain name is important for websites cause they are more simple to remember for humans. But for something like a game where no human need ever read it, accept the developer. Who only has to assign it to a variable once, and then can forget about it for the rest of the program. In that situation is it better to use a domain name, ip address, or is there essentially no difference between the two?

Mainly I just want to know should I bother to set up a domain name or just connect with ip address. What are the advantages/disadvantages to each method