Hypersomnia

Hypersomnia is an open-source multiplayer top-down shooter featuring pixel art graphics. The software functions as both a game and a development platform, allowing users to engage in combat or design their own environments. It is available as a browser-based application and as a native client for Windows, Linux, and MacOS, with native ARM builds supported for aarch64 architectures.

Users can deploy the game server via a Docker container or an AppImage. The application includes an integrated map editor that enables real-time playtesting of work-in-progress levels with other players, even those behind a router. The game features two primary modes, bomb defusal and gun game, and includes a faction-based narrative involving three distinct groups: Metropolis, Atlantis, and the Resistance.

Key features

• In-game map editor for community level design
• Cross-platform simulation determinism for synchronized gameplay
• Support for both browser and native clients on the same server
• 24 unique firearms and 10 community-created maps
• Integrated server infrastructure including a masterserver for server lists
• Discord integration for ranked matches and global leaderboards
• AI for fish and insects with flocking behaviors
• Automatic port forwarding for hosting servers from the main menu

The software is written in modern C++ without the use of a commercial game engine. It employs an Entity-Component-System architecture and a custom networking model that transmits only player inputs rather than full game states. This approach allows the simulation to remain deterministic across different operating systems and hardware architectures. To maintain this consistency, the project uses the Clang compiler and specific math libraries to ensure floating point calculations are identical across all clients. This technique minimizes network traffic, as only player-controlled characters contribute to the data stream, while environmental elements like bullet shells and AI creatures are synchronized locally.

Hypersomnia is positioned as a community-driven project for players and developers interested in open-source game development and deterministic networking.