Space felt a bit too safe once the asteroid defences were sorted, so I added something that fights back.

Space leviathans

Big segmented worms, like the Vulcanus demolishers, but in space. They only live on the routes you pick in the settings (Fulgora to Aquilo by default), so your early ships are fine. There are six sizes, from a 60k HP hatchling to a 600k HP ancient one, and the big ones hit a lot harder and drop more.

They bite chunks out of the hull, whip with the tail, spit acid and burn everything near the head. The attacks don't come on a fixed timer, so it doesn't feel scripted. After a couple of hits they start going for the hub. Kill one and you get a cloud of asteroid chunks, promethium included. Or just fly faster than 180 km/s and leave it behind.

Defences

• Energy shield - burns shield cells (you can make them right on the platform) and zaps incoming asteroids. Costs a lot of power. The dome gets brighter as it charges.
• Repair bay - fixes the hull while you're flying, using repair packs.
• Route scanner - sends the danger, length and leviathan info of the next route to the circuit network, so you can wait for the right moment to leave.

/leviathan-test 1 (or 2-6 for the bigger ones) builds a test platform and calls a leviathan in.

Космические левиафаны, сегментные черви на поздних маршрутах. Шесть размеров, от 60 до 600 тысяч ОЗ. Они кусают корпус, бьют хвостом, плюются кислотой и после пары атак лезут к хабу. Против них есть энергощит с куполом, ремонтный отсек и сканер маршрута для сети. Команда /leviathan-test [1-6] строит тестовую платформу.