A downloadable game for Windows

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NEW: We are woking on "Immune Defense 2024" you can read more and support us at Patreon.com/molecularjig.

Immune Defense is a strategy game about molecular immunology for big kids and grown ups (ages 10+).  Players use white blood cells to fight off real pathogens, using real surface proteins and signaling molecules. The immune cells are accurate in size and behavior; they look like they would under a light microscope. However, through video game magic, you can also see and use proteins! Immune Defense is what scientists dream about! 

Get the walk through for Level 4: You need it.  After level 4, the game opens up and you can see the potential awesomeness of the strategy game. 

The player can zoom in and out, looking in deeper, as if with a microscope, to see the details of the interactions between the white blood cells and the bacteria. 

Alec Slayden was the programmer that developed this version of Immune Defense.  His patience, willingness to iterate and his imagination really brought Immune Defense to life. Cosmocyte provided the art, although the splash screens are mine. Other game design help came from Jacob Clayman, Eric Martin and Jerold Council. 

This version of Immune Defense was funded by a competitive research grant from the US National Institute for Allergy and Infectious Diseases (NIH/NIAID).  

After 2014, work and grant writing continued. John Biddle contributed vital clean up code. Mike Halbrock, the most patient, talented, versatile game designer and C# wizard ever, was invaluable in creating this version of Immune Defense. Mike and I responded to the many, many, many rounds of play testers’ comments which really improved the player's experience a lot.  Finally, thank you to all my DC and Seattle play testers and friends. 

This version of the game was accepted into several competitive indie video game expos, including MAGFest, Gamescape and the Seattle Indie Expo (2015).

Please play it, express your support in comments and tweets, tell your friends!  All this helps me make more real, nitty gritty science games like Immune Defense!  

What people are saying about Immune Defense
July 2016 6 DC-born indie games you can play right now
July 2016 13 ways to jump into DC’s indie gaming scene July 2015 Here’s what you can play at Gamescape this year
January 2015 Rock, Paper, Shotgun by Shaun Green.
August 2014 Serious Game Market by Eliane Alhadeff.
July 2014 Binky’s Blog


StatusIn development
Rated 3.5 out of 5 stars
(2 total ratings)
GenreStrategy, Educational, Simulation
Made withUnity
Tagsbacteria, biology, chemistry, immune-system, Real time strategy, Top-Down, virus
Average sessionA few seconds
InputsKeyboard, Mouse, Touchscreen


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Click download now to get access to the following files:

Immune Defense PC.zip 54 MB


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Such a niche invention! I love it but,  it's much harder after the movement levels, may be you could easier it to bring more fun? Cause I don't wanna get stuck...

It's a lot easier with a mouse...  level 5 is pretty hard!!  Were you using a mouse?  Level 6 gives you the ability to get cells anywhere along the vein, which obviously helps a lot.  Also: to move cells faster, turn off all the receptors besides the move: with only move receptors on its easier to move cells.  

We are re-building the game, so we will be making the levels ... well, not easier, but the progression will be smoother!  

Yes I was using a mouse, the difficulty is "switching".

Switch the vein gates,  switch the receptors, and switch the cells, the tiny buttons... it's easy to fall into disorder.

And grabbing the protein is also not very smooth.

So improve the way of control? ; )


Just a suggestion, add other cells such as helper T cells, Eosinophils, etc

<3 Yeah! I intend to add more cell types!  We are re-coding it all from scratch so it will play on modern tablets and in browsers.  Then we will add more cells plus more microbes!!!!!  Keep in touch, I would love to know what you think! 


Awesome Game! Really fun and has taught me how the basics of immune systems work! 

Thanks!!  You can leave a review for this game and many others at ScienceGameCenter.org

Would Development Ever Continue?

I am trying to get some funding!!  Please keep in touch! ❤️ Thanks for asking!!

Very interesting game about the immune system!

Thanks!!!  :) I'm glad you liked it!!

I tried opening Immune Defense with the latest update on mac but it says the app has been outdated. Can you fix this issue?

Nope.  Sadly Mac changed their OS too much.  I am working on a new game and eventually an updated version of ID.  Thank you for your patience!!

We are making progress on the new version!  Just an update!

Linux version is not working... Why it only 7 MB tho..

The file is zipped.  When you unzip it it will still only be 18 MB.  But it should work.  Let me know!  I honestly have not tried it myself in a long time.

(1 edit)

After extraction, i only find executable file and no data folder like in Windows version…

I apologize. I will have to take down the linux version.  :(

when will it be updated?

Hi deepledi!  

This version of Immune Defense is a prototype for a large, RTS style game. I have 250 levels planned... but I need a team to make the full version.  What would you like to see?

Immune Defense taught me a lot about what makes a game fun and how to help people approach science and keep having fun.  

I am working on a mobile mini version.  The plan is, make a mobile, endless phagocytosis game and learn even more about fun while slowly building up my team and our audience.  

I will be continuing to blog at MolecularJig.com/blog. I hope you join me on the journey and  thanks for playing!!


id like to see the lung levels. the game so far is rather short and i beat all of the levels within a 30 minute - 1 hour time period

We would love your feedback, everyone.