Just change animations of the biters, spitters, spawners and worms into an army of humans. Non-game-changing, only change looks.
Small changes concerning balance, gameplay, or graphics.
You don't have a mod that reskins the Avatar into an Alien by any chance? A total reskin of Factorio into alien like things would be awesome, but i think i'm asking for to much here. So a reskin of the Avatar would be awesome enough.
