Couple of thoughts or suggestions for Rust
Do you think Perks/Experience would be a good idea?
The more you do a task, the quicker/better you become at it.
Or even restrict some activities to those with perks/classes.
Improved Archery (zoom option)
Runner (increased running speed)
Strongman (harder melee, throws spears further, carry more, slower running)
Weaponsmith (produces higher grade weapons)
Miner (better with pickaxe)
Farmer (can plant crops, can domesticate pigs, build pens)
Can’t decide on which characters/animals to include? Why not create a Multiverse (multiple universe) game (basically server options).
Like dinosaurs? Run a Land before time server (no guns).
Like Aliens? Add space ships and laser weapons.
Like COD? Have a modern day warfare server (or go play COD)
Apart from the animal/dinosaur/alien models, most differences only are about weapon availability.
That way you can cater to 99% of peoples wishes