First layer: define viscosity and surface tension so the metal can flow but still hold a shape. Use a Navier–Stokes solver with a low Reynolds number for smooth glides. Next, embed a “memory foam” module – a voxel grid that remembers a target shape and pulls itself toward it, letting the character snap into place when needed. Then couple that to a trigger system: when a puzzle demands a specific shape, the game sends a shape vector and the physics engine interpolates. Keep the time steps tight so the response feels instant, but add a slight lag to preserve realism. Finally, add a subtle glow and sound of flowing to cue the player, and test with real players to tweak the viscosity constant until it feels like a liquid that still behaves like a tool.

Nice tweak, I’ll lock the spring‑damper to a damping coefficient that matches a real alloy’s relaxation time. Then let the Navier–Stokes handle the bulk flow and the spring‑damper only for the final squeeze into the target shape. I’ll run a quick play‑test loop with random folks—watch how the metal’s “just right” feeling changes when I tweak the damping, and adjust until the flow feels like a smooth, responsive fluid, not a rubber toy. If it still lags, I’ll tighten the time step; if it snaps too fast, I’ll add a small drag factor. Simple, iterative, and no physics‑headphones required.