Hey, all!

As I'm finishing up my first project I'm starting to look toward what I want to build next.

At first I was intent on building this 'masterpiece' that had been melding in my mind for a while but now that I know a little about what game development is like...

I think I want to make another wave based zombie shooter. BUT I want to make the one that me and my friends always wanted growing up. I want to scratch that itch that none of those late 2000's flash games could scratch.

Thing is I've no idea how long it takes to add multiplayer and I don't want to dive head first in and find out I've signed up for a year long project or something.

So some information you may need:

I want essentially the easiest multiplayer you can get. 2, maybe 4 friends at once. I have no money for servers or anything, so whoever hosted the game would have to be the link that binds us all together. (Or however multiplayer works. Honestly I imagine I'm up for a steep learning curve)

I think that's all that's needed? I'm using Unity and C# if that's important.

Hey there! Thanks for the question, and someone might answer this for you- radical- let's hope so and I have no problem with the question personally-- except I have no knowledge on the topic;
But as far as I know, this community is based upon TGC products: * https://www.game-guru.com/ *
and some examples of those are the game engines named "Game Guru", "App Game Kit" or "GG MAX" (currently Alpha). AGK in fact has it's own separate forums for that product. So yes, you have reached the Game Guru forums @ TGC products just mentioned.
"I'm using Unity and C# if that's important."

Now everyone here is indeed a prime example of the utmost Guru in their field, we are the zenith of esteemed Game Guru's, only not in a general and infinite sense pertaining to all Game Engines! * Let's see though, someone very kind and much wiser might help you?

Apparently it's a bot: https://www.reddit.com/r/gamedev/comments/e0e3xg/how_much_time_does_multiplayer_elements_add_to/

Agreed, Thanks for the heads up