The pond is water now

For its first week the pond was scenery you could stand on. Now you go in. You swim, you can drown, fish live in it, and the rod finally lands what you hook.

Swimming, with your hands

Pull your arms back through the water and the water pushes you forward. Only hands under the surface count, so flailing above the waterline does nothing. Fully underwater you always drift up, so drowning is somewhere you swim into, never something that happens while you learn the controls.

You get thirty seconds of air. The meter only appears when your head goes under, and it refills in four seconds.
From below, the surface shows a bright window straight overhead and a silver mirror everywhere else. The world above goes blurry and quiet.
Water carries things. A light log bobs at its own waterline, stone sinks, and a chicken paddles to the bank looking furious.
Water puts fire out. Dip a burning stick and it hisses.

Fishing that fishes

The cast used to sail clean over the pond. Now a tap lands just off the near shore and a full hold reaches the far side. A dry cast says NO WATER instead of pretending to wait for a bite.

The pond has fish in it now: twenty species, common to legendary. They wander, scatter when you come at them, and jump. When you catch one, it's the exact fish you were watching, at the size it was in the water. The rod itself is something you make: a hardened stick in the lashing post, strung with spider silk.

Something in the caves fights back

Cave spiders ignore you until you hit one. Then it comes after you, up the wall and onto the ceiling. It bites your actual body, so ducking and leaning away genuinely works. The hunt stops at the cave mouth, where it paces while you catch your breath outside. Kill one for silk.

Dying got real, too. The screen washes red, your body is thrown, and you open your eyes on your own corpse. Getting hurt reddens the edge of your vision, and under a third of your health it stays there.

Tools that aren't the same tool

The pickaxe is for stone, the axe for wood, the sword for flesh, and the wrong tool lands with a dull thud. Fists and a plain rock still work on everything, just slowly. Before any of that, you can tie a rock to a stick with grass in your hands: a crude tool that does every job badly and falls apart after about a dozen hits.

Smaller changes

Every player wears one of twelve earth and mineral hide colors.
Every animal shows a health bar.
Meat cooks set down beside a lit campfire, not only held in it.
Circle one hank of grass fiber around another and you get rope.