I made a Web shooter in C++ with no engine. Fully deterministic netcode

In plain words

Hypersomnia is a web-based multiplayer shooter built in C++ without a game engine, featuring fully deterministic netcode that synchronizes complex Box2D physics across all clients using IEEE754-compliant floating-point math. Players compete in ranked matches through browser or native clients on Windows, Linux, and macOS, with matchmaking based on the OpenSkill rating system. The project includes rectpack2D, a texture atlas packing tool that has been adopted in commercial games and academic research.

written from the facts on this page · September 2026

From the sources

Hypersomnia is a free-to-play competitive 2D top-down shooter with intense gunplay, tactical gameplay, and stunning pixel art. Join fast-paced bomb defusal matches, clan wars, and duels in this open-source multiplayer game.

Experience the intensity of Counter-Strike combined with the fast-paced mechanics of Hotline Miami . Available for Windows , Linux , and macOS . The download size is under 50 MB . All archives are digitally signed for authenticity and integrity. Verify them here using publicfrom hypersomnia.io

In the maker’s words, at launch

GitHub: https://github.com/TeamHypersomnia/Hypersomnia - The netcode relies on full simulation determinism - this includes Box2D physics. I'm using standard floating-point calculations and rely on IEEE754 compliance. I also use STREFLOP for portable math function implementations. This is commonly…

• 
  Open-source shooter which made it to AC: Valhalla and Skydio drones2023 · github.com · ▲270

  So just for fun, I wrote a complete multiplayer game in pure C++. I even wrote my own texture atlas packer, which is now used by Assassin's Creed, 2 scientific publications as well as a drone manufacturing company - each of these basically mentions the name of my game. There is even a claim that Unity patented some of the ECS ideas that originate from this project. See https://github.com/TeamHypersomnia/Hypersomnia#tech-highligh... for details. By the way the game is pretty darn good. 10 people connected yesterday to test a new map:…

• 
  I made a Doom-like game fit inside a QR code2025 · github.com · ▲531

  I sometimes pick up random projects just because I can, this was one of those times. I made it as a week long project a while back this year but never shared here, so thought to go for it haha. I created a game inspired by Doom and the backrooms called The Backdooms under 2.4kb in minified html. (for reference, this entire post would be around 1.8kB haha) I had to use a not popular way of using GZip with Zlib headers (had to write my own script for compressing it, also in the repo) to eventually convert it a size 40 QR code that works right in your browser using Decompressionstream API. This…

• 
  I wrote my own RTS game engine in C2021 · github.com · ▲1,102

  An OpenGL RTS game engine written in C. Contribute to eduard-permyakov/permafrost-engine development by creating an account on GitHub.

• IM
  I made a browser-based RTS game2022 · battle-of-flags.com · ▲212

  I've posted this game here before, hopefully a repost is fine as the game has changed quite a bit (improved AI, improved mapeditor, much quicker gameplay, etc). Game is based on JavaScript/Canvas and WebSockets. On the browser side the map is pre-rendered (as a background image), just the mobile units/buildings and animations are dynamically rendered. The lobby server is made in node.js, but the game server is C++ for performance reasons (mainly the pathfinding). I found the C++ WebSocket libraries out there to be too difficult to use so I made my own based on the rfc. Overall I…

• 
  A Marble Madness-inspired WebGL game we built for Netlify2024 · 5-million-devs.netlify.com · ▲616

  Hello HN! We’re a small creative studio specializing in real-time 3D experiences. Netlify approached us to design and build an interactive experience to celebrate reaching 5 million developers. Inspired by the classic game Marble Madness, we created a gamified experience where users control a ball through playful, interactive levels. The goal was to blend marketing content with the look and feel of a game to engage users. The app is built with Three.js [1], using our custom render pipeline and shaders, and uses Rapier for physics simulation [2]. The 2D content is overlaid on the WebGL view…

• 
  I'm open-sourcing my game engine2023 · github.com · ▲318

  Modd.io is a collaborative game editor that runs in browser. It's kind of like Figma for game dev. We made this engine low-code and multiplayer-first, so developeres can quickly prototype casual multiplayer games. I hope some of you guys will find this useful. Would love to hear feedback also. Thank you. Engine Demo: https://www.modd.io

• 
  /dev/null▲468

  a social network for devs

  Dev tools · 2d ago · dev-null.sh

• 
  Whiteboard (YC W26) – an open-source IDE for thoughtful software design▲423

  open-source IDE for thoughtful software design. Contribute to devdotfast/whiteboard development by creating an account on GitHub.

  Dev tools · 27d ago · github.com

• 
  Reladraw – A diagram language where you decide where to place things▲411

  Contribute to reladraw/reladraw development by creating an account on GitHub.

  Dev tools · 25d ago · github.com

• 
  OpenBot▲362

  Grok Bot alternative: free, local, open-source, multiplayer

  Dev tools · 22d ago · openbot.run

• 
  Talanoa▲340

  Hi HN, I’m a fullstack developer, and honestly, I’ve lost count of how many side projects I’ve worked on over the years. But one idea kept coming back to me: a different kind of email client. It first came to me in 2014: “What if we could handle emails more like conversations?” Every year, I’d revisit this concept in my “Build Notes.” Ten years later, no one had built exactly what I had in mind — so I finally decided to do it myself. That’s how Talanoa was born. I wanted something focused on people, not timelines. I was tired of marking messages as unread just to remember to reply later, or…

  Dev tools · 20d ago · talanoa.email

• 
  CoreSpeed▲332

  One MCP for everything your agents need: apps, memory, tools

  Dev tools · 27d ago · corespeed.io

• 
  Pygma▲1,412

  AI copilot for Instagram

  AI · 2024 · pygma.me

• 
  Cello▲1,347

  Easiest way to add a referral program to your SaaS

  Growth · 2024 · cello.so

• 
  La Growth Machine▲1,216

  Create personalized, multi-channel conversations at scale

  AI · 2024 · lagrowthmachine.com

• 
  Superhuman 2.0▲1,142

  Revolutionary AI email, reimagined for teams

  AI · 2024 · superhuman.com

• 
  FlowMapp 3.0▲1,142

  Visual website planning in the most powerful way

  Work · 2024 · flowmapp.com

• 
  PyjamaHR▲1,132

  Hiring on autopilot. The AI applicant tracking system (ATS).

  Work · 2024 · pyjamahr.com