• Its own bestiary: eight creatures with 3D bodies; two new subs, Saucer and Kettle
• New rock and living walls at every depth; some plants reach for you
• Worm swarms that flow like a shoal; the sub fights back with electricity
• Charges tear swarms apart; flares burn eggs and worms
• Currents you can see and feel
• A controls lesson, a calmer screen, a lamp you can aim
Abyss Brood is an experiment, not a finished game.