KinematicSoup

08/29/2026

Mutant Mayhem: two years in development as a single-player game, converted to a 4-player match in three days. KamJam Games had never written networked code. The case study covers the timeline, what broke, and the move toward server authority that followed.

https://www.kinematicsoup.com/blog/mutant-mayhem-single-player-to-multiplayer-in-three-days/

07/31/2026

Reactor 1.1.3 and Scene Fusion 2.0.5 are out. Unity 6.5 support across both products.

Reactor 1.1.3 adds per-room network statistics (ksRoom.NetStats, plus a component that feeds them to your own callbacks), experimental UDP client frame syncing, and a batch of physics and spawn fixes.

Scene Fusion 2.0.5 adds terrain settings sync and full prefab syncing fixes, and now supports Unity 2022.3 LTS through 6.5.

Install locations are here:
Reactor: https://www.kinematicsoup.com/reactor/install
Scene Fusion: https://www.kinematicsoup.com/scene-fusion/install

Install Scene Fusion for Unity via Package Manager. Free for teams of two.

07/31/2026

We always love Synty Studios assets!

07/28/2026

Reactor 1.1.3 is live!

Update directly from the package manager or check out install page for instructions https://www.kinematicsoup.com/reactor/install

Install Reactor for Unity via Package Manager. Free to develop locally, free to self-host up to 32 CCU.

06/17/2026

If you are budgeting for a multiplayer game, the servers are usually not the expensive part.

We worked through the full monthly cost of building and running a multiplayer backend: bandwidth, compute, backend services, and the engineering to build and maintain it. For a 32-player shooter averaging 300 concurrent players, the infrastructure came to about $1,465 a month, while the labor to build and maintain the custom netcode came to roughly $8,650 a month. For most teams, the engineering time is the number that decides the budget, not the hosting.

We wrote it up as a practical guide, and we built an interactive calculator so you can plug in your own game (player counts, tick rate, entity counts) and see where the money goes. It includes presets for FPS, extraction shooters, and MMOs.

Read it here: kinematicsoup.com/blog/how-much-does-it-cost-to-build-and-run-a-multiplayer-game

05/28/2026

This is online multiplayer - 2 players vs up to 5000 enemies, fully synced at 50-70Kbytes/s using snapshots using Reactor Multiplayer Engine with Unity + DOTS as the client.

Reactor's compression is reducing the transform updates to < 1 byte automatically. All we did for tuning was set the precision level, and the update rate (15hz), the algorithm automatically minimizes data within those parameters. Rotation is inferred from motion, so while the update contains space for the rotation info, the compression system detects it is unchanged and automatically minimizes its contribution to < 1 bit per object.

If Reactor sounds interesting to you, check out our website at https://www.kinematicsoup.com/

05/25/2026

Evaluating online multiplayer solutions like Reactor, Coherence, or Photon? We put together post with a comparison and some of the factors to consider. Check it out here: https://www.kinematicsoup.com/blog/reactor-vs-coherence-unity-multiplayer

A technical comparison of Reactor, Photon Fusion 2, and Coherence for Unity multiplayer development: server authority, bandwidth efficiency, hosting costs, and complexity at scale.

01/21/2026

Imagine if you could build multiplayer games where the sky's the limit on the action.

Check this out: Reactor Multiplayer Engine + Unity DOTS in a game prototype where players take on mobs of absurd size - 10,000+!

This has never been done before in a state snapshot system.

You can get reactor today: www.kinematicsoup.com

Join us on discord: https://discord.gg/vWeTvPB