In my introduction I revealed that my son and I are working on a project to eventually put into an arcade box we'll build and put in the game room/ man cave.  He had never screwed with MUGEN, and I thought I hadn't since 2006/2007.  Well I found some old posts of mine on mugenfree4all from 2012, so I guess I was wrong.  Anyway, he has started animating sprites, and I've mostly been hunting down resources.  The beginners guides I've found here and other community sites have been amazing.
So we have not fully hashed out what our end game will be, but these are the things I know for sure, and would appreciate any inputs, lessons learned, pitfalls to avoid, resources to utilize, etc. that you are all willing to provide.
He likes:
Naruto
Death note
JoJo's bizarre
Persona

I like:
Mega Man and X
Castlevania
SF
MvC
Tekken
Seven Deadly Sins
HunterXHunter

Like to include at least 4 Characters from each series with at least 1 stage and one mp3 for each.  Starting with a simple 1v1 versus mode.

I know we will want to "plug and play" several of these things, but we'd also like to build some of our own from scratch, except music.

Having never done anything like this, I'd like to know how the community balances things like size differences, graphics quality, and is there a standard or bar for what makes a balanced character, an OP one and a broken one.

Assume we've never seen MUGEN.
What would be the min system requirements to run something smoothly, and what changes those requirements?
Where would you tell us to start, and what are your fav resources and why?
Thanks for whatever input you may provide in advance!

Thanks! You guys are awesome! I'm a fan of nostalgia, so I doubt I'll be pushing any super HD/4k /8k/in front of me real in life builds. I think we'll be good rocking up to about PS2/XBOX quality work for this project. Maybe dip a toe into the graphics generation after that. So far I've been learning as much as I can reading files and the tutorials that come with 1.1. Lot of educational stuff in there. Gearing up to tackle spr.mkr and try to do some bgs... I am wondering what the code would be to set a couple/three mp3s to play randomly at, say the title screen, so you don't always get same tune. Tried "bgm= sound/songname1.mp3, song name2.mp3, random" "bgm= sound/ random" and "sound/songname1.mp3, song name2.mp3
No luck. I could just create an mp3 medley, but it would still always be the same...

Update/follow up question:
If no random bg music command, is there a command for more than one bgm? Can mugen utilize other programs via its own code?
So far we've got about 25 stages, and a little over 100 chars. I was reading on here that 40-60 chars would be optimal? A good part of the currently loaded roster are dif versions of the same characters for play test purposes, so final roster will definitely be less. Found out that most of the Naruto characters, which my son loves Tobirama so have to include him, are JUS. Just learned about this, so maybe you guys can pass me some knowledge? My favorites are Ryu, Akuma, Kazuya, King, Strider, Megaman, X, Zero, Alucard(SOTN),Scorpion, Heihachi and Smoke. The fully functional ones of these i can find have been MvC/CvS styled for the most part. In fact, found few if any compatible/working MK, Tekken, MM/X characters. Should I attempt to make 2 games, is there a conversion method or helpful guide for size/move set conversion from JUS to what I'd call normal and vice versa? Should I just try to build the fighters I want in the format I want from scratch?

Joe_Daddy1979 wrote:
If no random bg music command, is there a command for more than one bgm?  Can mugen utilize other programs via its own code?

Mugen is a closed source application. Elecbyte the developers, released the final Beta in 2013 and have been absent from the community ever since.
This means that if a feature is not listed as available inside the Mugen DOCS folder in your mugen directory, sadly it is not available.
You may want to have a read through there as you may find some helpful information and learn of features that were not available in mugen when you originally were using it years ago.

Joe_Daddy1979 wrote:Should I attempt to make 2 games, is there a conversion method or helpful guide for size/move set conversion from JUS to what I'd call normal and vice versa?  Should I just try to build the fighters I want in the format I want from scratch?

Sadly there's no cut/paste guide when it comes to character creation.
on the brightside there are more resources available on youtube and in forums and the updated mugen DOCS files that wouldnt have been around when you were using mugen many years ago.

As far as making 2 games and characters from scratch, it all depends on what your overall goal is and how much time you have daily/weekly to use on mugen. Building a character from scratch if you have never done it before will be a learning curve to say the least and will be 10s of 10s of hours work.
Something to keep i mind

xXEnchanter.ZuXx, Vermilion Spy, Phant0mD, Ex-Sirius,
I really appreciate all of your responses. I retire in about a year and a half and like to think I'll have all kinds of time then. Not likely. These days I take leave so I can work, so I don't have bunches of time, but I have drive. This thing's on my bucket list. When I've created some original content(if?) I'll share and ask for criticism. My wife gave me some pretty good ideas for some bgs. I'm not super artsy, too logical, or at least my creative side has been stunted due to the need to cultivate the logical

Can we place bets on whether you complete an original fullgame by december 2021?
lol.

Sure, but I'd bet against. I have no intention of creating a full, original game. I'm a giant shoulder stander! I do want to create some original things for it though. Couple Bgs, I or 2 CHARS. and maybe some working original script/coding if I can advance that far...

Sometimes you don't have time... speaking of, what's the standard for trashing a thread? 90 days does seem reasonable. Work has had me so busy I didn't realize it's March, and I haven't shared any progress because I have not created anything original yet... can this be resurrected when I do?