Hanging around: vines you can climb like Tarzan
The grass tufts from the vegetation pass always felt like decoration. Nice to look at, but nothing about them changed how you move through the world. So I gave them a job: grass blocks can now grow vines that hang down from their underside, and you can grab those vines and climb them like Tarzan. Watch:
Vines grow on their own
The vines are not placed by hand. Every few seconds a growth tick samples the world: vine ends that can extend grow one tile further down, and every grass block with air underneath has a small chance to sprout a fresh vine. Leave a hillside alone for a while and the green curtains slowly creep downward. Vines also sprout under grass blocks you placed yourself, and each column stops at a maximum length so the world does not drown in green.
The growth is tuned through config like everything else: tick interval, growth chance per tick, sprout chance and the length cap. Scattered growth instead of lockstep matters here, because a whole row of vines extending at the same time looks mechanical and fake.
How the climbing works
The rule is simple: while your body overlaps a vine tile, you hang on it. No button to press, no interaction to trigger. From there, holding jump climbs up, holding down slides down, and left and right shuffle you slowly along the column. Let go of everything and the vine slowly lets you slide: it is a bit slippery, so you never just freeze in mid air. Water beats vine, by the way: a flooded vine tile is water first, so diving past a vine into a pond works as expected.
The animation reuses the walk cycle. While you climb, the character shows the scramble pose, arms and legs moving whether you go up or down. It sells the climbing far better than a frozen sprite would.
The tricky part: jumping off
Climbing to the top of a vine only presses your head against the grass block it hangs from. The ledge you actually want is sideways. That is what the vine hop is for: a fresh jump press while exactly one direction is held launches you off at full jump strength and full run speed, so you can mount the ledge the vine hangs from.
The fiddly part was the latch. After hopping off, your body still overlaps the vine column for a few frames, and without a guard the climbing logic would instantly re-capture you mid-arc. So a hop sets a latch that keeps normal physics running until you have actually left the vine. It also clears the moment you start falling again, which fixed a subtle case: hopping sideways from one vine to a neighboring column never leaves vine overlap at all, and without that rule you would fly straight through the neighbor instead of catching it.
A new way to move through the world
What I like most is what it does to the map. Ledges that were just out of reach, overhangs you had to mine around, cliff sides that were pure decoration: all of that is route now. Climb up, shuffle over, hop off, and the terrain reads completely differently.
No promises about what comes next, in the usual no-plan way. Maybe cave vines, maybe a rope, maybe I just spend another evening hopping between vines like an overgrown kid. Follow along if you like.