I found a hardcore SMP called Unstable HMP that tries to copy the Unstable experience. It has custom terrain made to match the Unstable Universe series so the world feels familiar but still dangerous.
Deaths matter a lot here. The hardcore ban is one week and your enderchest gets wiped. That means you have to play careful and think ahead.
The server includes special terrain like the Farlands and the Underworld plus more areas like that. It is meant to feel unpredictable and intense.
It also pushes people to team up. There is a free civilization anyone can join called The Golden Circle. Builders and PvPers and redstoners and trappers can all join and try to survive longer together.
