Nela System
Based in Shanghai, China

Release date:



Regular Price:



Signal Decay is a rogue-lite action game set in a future dystopia with unique cooperative stealth gameplay. As the only human beings to have escaped the global manipulation of mind-control technology, you are called upon by a mysterious computer to save the world. Signal Decay is about player communication and coordination. It is where XCOM meets Monaco -- combining the experience of coordinating XCOM operators with interations of Monaco. Players infiltrate military bases with reactive defense systems. Each action has an instant effect and longer consequences, and a strategic decision is a balance of risk and benefit. Coordination is always the most important factor for a successful mission, and trust is the antidote to the ever-escalating pressure.


Signal Decay was originally an MFA thesis, SAVIORS at NYU Game Center by Zack Zhang. When the project started, Zack wanted to make a replayable cooperative in which players need to communicate and coordinate. Players solve emergent problems in a complex system, which feels like a dynamic agent movie as well. There was no game quite like this. The thesis ended with a playable demo with basic mechanics on tactics. After Zack Zhang graduated, he decided to start a company and continue to develop this game. The game was renamed to Squad Of Saviors then, and won IGF China finalist afterwards. The gameplay was further iterated and changed a lot after that. During the game development, NYU Game Center community was very helpful. Playtest Thursday and advice/suggestions from people there provide very useful insights to make the game better and better. Zack returned to China in 2017 to continue developing Signal Decaydue to visa issues. It didn't go very well to build a team to finish the game. He ended up working on his own, with a few excellent freelancers contributing a few months of their work. There was a plan to release Signal Decay in 2017, but Zack didn't think it was ready. And the early access version was finally completed in Sep, 2019, way later than expected.


  • Designed for 1 to 3 players to play.
  • Unique cooperative stealth gameplay.
  • Second strategy layer in which players piloting an airship to find a path to complete the operation successfully.
  • Using weapons and equipment to customize gameplay.
  • Collecting and managing resource to unlock new technology, build ammunition, and heal.


Trailer YouTube


download all screenshots & photos as .zip (8MB)

download logo files as .zip (137KB)

Awards & Recognition

  • "SXSW Gamer's Voice Nominee" Austin, March, 2020
  • "IndiePlay Excellence in Innovation Winner" Shanghai, July, 2016
  • "Indie Prize Official Seletion" Casual Connect USA, July, 2016
  • "Indie MINIBOOTH showcase" PAX East, Boston, MA, April, 2016
  • "IGF China Main Competition Finalist 2015" Shanghai, October 10th, 2015
  • "BostonFIG Official Selection" Boston, MA, September, 2016

Selected Articles

  • "Colorful and readable and pretty distinct from everything else on the market right now."
    - Akhan, HandsomeTrustWorthy
  • "So much of the modern co-op gaming scene is focused on hectic action games which are more about reflex than planning. Signal Decay looks to change that."
    - Marcus Estrada, Hardcore Gamer

Dev Blog
Development progress. Notes on design & technical problems and the process solving them. .

Steam Greenlight

About Nela System

Currently a solo indie game studio founded by Zack Zhang. With formal training on game design at NYU Game Center, we are here to create novel gameplay letting players tell their own interesting stories.

More information
More information on Nela System, our logo & relevant media are available here.

Signal Decay Credits

Zack Zhang
Creator (Designer, Artist, Programmer, Sound Designer)

Michael Song
PR manager.

James Cao
Visual Designer.

presskit() by Rami Ismail (Vlambeer) - also thanks to these fine folks