I like the idea of having 100K cycles with mutations before the fight... although it may be hard to actualy pick wich of the mutated bots are to compete....
And I realize the idea is near impossible to get to work as a propper league... I just hate how most of the good league bots break down after a few mutations. They either turn into canibots because the conspec is way too simple, this goes for almost all league bots, or they break some vital part of the code or generaly devolve the complex behaviors...
But most of the sugestions posted so far require a larger field with less veggies... if a multibot is going to compete in a league, then it needs time to form and generaly get started, so you can't have oponents spawn right next to it that don't depend on forming an organism.
And in a way the simples organisms are the strongest, not just in DB... viruses and bacteria will always be around, long after we're extinct.
So in my mind if you want to set up a league that favors more complex organisms you need a much larger field with a limited amount of veggies, and you need to set the rules in order to prevent most of the things that make bacteria like species superior. So for instance no killing with ties, no venom, no mem shots, no viruses, no tie feeding (Ofcourse you can share energy with your own kind... possibly also with veggies, although it would be more challenging if you can't just tie to a veggy and make it part of your organism, and allowing to share nrg with alge will just help the small bacteria like species.)
Either way I think it would be possible to just make a league with all the right rules and settings to favor multicecular organisms.
And with no venom, tie killing or mem shots (And ofcourse no sexrepro) then fungus species shouldn't be too powerfull since they need to grow if they want to kill anything. I don't know exactly what the rules and settings should be, but I think you can balance it right for multibots.
I also love the neural net league idea I have an evo sim I've been running about 500 hours with a neural net with a very redundant structure for the weights in order to encourage changes in the weights rather than breaking down the whole thing too fast...
So far I've gotten way more out of that sim than anything else I've ever run. They have a balanced use of shell, I think they start with about 500, then make more if getting shot at and remove some if they end up with too much shell after a fight. They don't kill the alge but guard it instead eating a litle at the time while moving it around (Not using ties, just realy good ball controll). They hamster energy and reproduce rapidly if they're in too much pain in order to escape. If they get too big and risk killing the alge in few shots they create a big offspring and start over on the alge. They have a very stable conspec, there are no carnivores or cannibots evolving... had a few carnivores pop up now and then but they never lasted, the bots are too good at escaping if they're loosing a fight. They'll shoot at litle at anything they see, but they try to maneuver around their own kind avoiding confrontation, unless there's an alge close by then they fight for it (I have no idea how they can keep track of that), and ofcourse if one of the bots is agressive the other one will defend itself. Also the latest evolution I saw was a bot that instead of being realy good at guarding the alge it got realy good at stealing it, so when it sees an alge it makes like a big you turn to accelerate then swoops by and takes off with the alge. It completely looses sight of the alge while doing this but it works rather well... only problem is that this behavior makes it less good at keeping the alge since it's ball controll isn't as great. (I've watched the "guarding" species hold an alge for ages without loosing it despite many compeditors trying to take it, it accelerates the alge by pushing it, then slides around the alge changing the direction, and it does it realy well, it would beat me at soccer any day.)
Ofcourse I haven't tryed implementing backpropagation and such to make it manualy adjust the weights, but just mutating the weigths in a redundant network gives great results from what I can tell... and some of the behaviors aren't just from changing weights, for instance it evolved a handicap on one of it's movement directions because this stabilized it, but not by using the existing structure. So once most of the network is used it starts to change and do other things that weren't planned for.
So it might actualy be possible to make an evo league for blank neural networks... might also reveal some clever ways of prepping a network for mutations.
Not as sure about the antbot league and single organism league... sounds like it would be hard to get the organism league working... and the antbot league may not end up being very different from F1 depending on what other rules are set up. I mean you could probably make fruitflies employ a queen somehow... just let the queen spit out the flies and let them go feed and come back with the energy... the rules need to encourage complex behavior and not just require it. Otherwise it'll be the same bots we have now just with some added complex behavior... no sure how to set up rules to encourage antbot behavior... otherwise there's the IB league atm, wich I think is kind of something along the antbot league you're sugesting.
But I think it's possible to make a league that encourages multibots, and I definately like the idea of a NN league, but thats probably just because I'm a big fan of NN's.
And I also think new league will fill up over time... the only reason the SS league is half empty is because it's so damn hard to get an SS bot to work... and possibly because of the nazi assosiation, who knows...