Dan mentioned how artifical gravity would lead to Super Mario Galaxy and I can't stop thinking about it so here's some teeny tiny worlds.
The Messinger-Dawoud KV/4 Gravity Engine
Delicate golden filigre, layer upon layer, surrounding a woven coccoon that spins it anew as the outer layers boil away into vaccuum.
Intricatly carved wooden puzzle. Each layer increases in difficulty. Desperate debtors crawl across in vaccsuits, feverishly working to unlock chests of air and supplies.
Transparent orb, filled with a freshwater ecosystem. Waterproof false sun at the center, shrouded in oxygenating plants. Amphibian servitor-creatures croak in a choir across the comms.
Earth and stone and conifers. Thin atmosphere, alpine climate. Single 'mountain', populated by a lone shepardess and her goats.
Layer upon layer of books. Tunnels within carved by librarian-hermits.
Dirt, graves and bones. Shaped like a skull. Ring of dancing skeletons animated by wires. Coven of goth cyberwitches inside- quite friendly once you get past the cobwebs and corpses.
Giant hermit crab. Snips at passing ships.
Enormous flowers arranged around a central core of glass. Bee-drones hum in a swarm. Wealthy owner LARPs as a fairy queen, has had psychosurgery to make herself more whimsical.
Ball of sand and rock. Some large cacti and some lizards. Lone gunman in a vacsuit plays the banjo mournfully. Half-heartedly raids passing ships.
Very large CRT monitor. Cassette-cultists make their home inside. Hum of ozone, dust everywere. Watch out for static shock.
Dodecahedron of beds, each containing a slumbering wizard. The dream-world they inhabit is many times larger- passing spacers may find themselves lost in it when they go to sleep.
Collection of giant bottles, cocktail glasses and paper umbrellas. Zero-g globs of booze float in orbit.
Box-shaped collection of networked android logic cores, thick atmosphere protects from solar radiation. Narrow passages allow maintanence drones.
Spherical hedge maze, pavilions at each pole. Tea parties held on the hour every hour. Lots of rabbits and intricatly carved topiary.
Appears as a giant bread roll. Interior an industrial bakery, the android bakers have pastry-themed chassis.
Really big dog in a very large dog bed. Has a very large dog ball he wants you to throw for him.
Hamster cage. Different areas accessed by rolling in a giant hamster ball. You can walk but it'd be gauche.
Ridiculous brass contraption with no rhyme or reason. Pipes, tubes, valves and pistons go in all directions. Mouthpiece at the center- when blown the sound is indescribable.
Gigantic top hat. Interior contains a golden-lit ballroom, 24/7 parties and galas. Inhabitants wear long-nosed masks, black and white dress clothes. Speak in impenetrable references and gossip.
Giant sphere of crocheted yarn. Interior hollow, lined with pillows, blankets and softly glowing lamps.