Hello. Wondering how well multiplayer games where you have to enter an IP address do in the market as far as selling one or for free?
I'm also curious how many people play this type of multiplayer, so if you do, please drop a comment!
Which market?
And which IP? Local?
The vast majority of people will not even be able to enter an IP adress to connect to each other, even if they wanted to. You need port forwarding for that and find out your external IP adress to even start. That can be dealt with of course, but this is deprecated for just about any application. Some olden games that need such things can be played over special software that basically emulates a local network with vpn techniques.
Ask people nowadays to enter IP adresses and they will think you are trying to "hack" them.
Because of the router firewall, you need some kind of brokering. Itch does not have this. Steam has, and they are the market. So to answer your question: it is nonexistent in a commercial market. A game will just use the tools of the game platform to broker a multiplayer match, or have it's own server.
Maybe some enthusiast will give insights to this, but I doubt that there is a nieche group that likes games because of that, as there is for pixel art or text games. It is just not done anymore for lots of technical reasons to enter IP adresses to play a game together.
Honestly, asking players to type IP addresses feels like friction now. I get the nostalgia, but most people expect click-and-play matchmaking. I’ve tried explaining port forwarding to friends before, and that alone killed interest. For small hobby projects it’s fine, but commercially I think built-in matchmaking or a simple relay server is almost mandatory today.
The IP4 address is only valid in your local segment and not unique beyond that. Plus you'd usually be using dhcp. Which means your computer gets a new IP4-address every time your computer reconnects to the network. You'd have to find out your current IP4-address again every time.
There are definitely better alternatives which work between players world wide without bothering them to type in long number sequences. For example a public domain client-server solution. The server is just a piece of software that can run on one of the computer you are playing at.
I'm haven't looked for a HTTP server recently, the only one I know is Apache Tomcat which is free. There are however also multiplayer functionalities in game engines as well. I know the Unity engine has it (and I bet the Unreal engine has to have it too). The Unity engine and the Unreal engine aren't free in case you make substantial money with your games. But they are free for hobbyists. You'll want to check out your different options of game engines considering you want to do multiplayer.
Some of the software is free.
You still need a server that is reachable over the internet by dns and runs that software. Which for commerical games means renting server capacity and registering a domain name. It's a similar topic as how to run your own website.
If you have a server that runs on one of the player's machines, you need that player to overcome the router issue. That's not that hard, but it's a hassle for casual players. You need some port forwarding and use ddns or rely on finding out the external adress and giving those to the other players.
Maybe there is a free service somewhere for connecting machines to play together. But I guess that's hard to find. Multiplayer games are usually commercial or have local multiplayer. I quick search came up with some adware services and I do not know how trustworthy those are. Also it seemed like they were running the game, not merely connecting the machines.