Undersphere

Undersphere is a multiplayer first-person shooter set on the inner surface of a spherical world. Players run across the curved interior, fight each other, and try to outmaneuver opponents while gravity pulls them toward the sphere's shell instead of a flat floor.

The setting shapes everything. A grenade thrown toward the far side of the map stays under the sphere's gravity and travels with believable proportions, so distant targets and overhead arcs become part of the fight. The creator also designed its own movement mechanics, aiming to keep them fair and conventional enough for shooter players.

The game placed 14th of 945 entries at Vibe Jam 2026 and received the Unique Concept award. It runs in the browser on Three.js, and the creator says it was built with Cursor.