Playing Fortress Destroyer

Fortress Destroyer has become quite tricky to actually play, with Unity’s web player being deprecated. Here are some instructions based on what worked for me (a long time ago now — even this may not work any more!):

Uninstall Unity

Use the control panel to uninstall any Unity web players you might have accumulated while trying to run this game.

Install an old 32-bit Firefox

The 32-bit is non-negotiable, but how old I am not sure — too early and the NK login won’t be able to use captcha, too late and Unity won’t be supported. Version 50 definitely works; feel free to check a more recent one and let me know in the Ninja Kiwi Discord server if it works so I can improve these instructions.

Such an old version should not be used for everyday browsing. If Firefox is already your preferred browser, don’t worry: you can continue using a 64-bit version alongside this one, or you could consider using a separate Firefox-based browser such as Waterfox.

Disable updates

Go to about:preferences#advanced and select “never check for updates”.

This is very important, because left to its own devices, Firefox will automatically update to a 64-bit version if your computer supports it.

To be safe (or if you want a browser to play SAS4 on), go to about:addons, click the cog button at the top of the plugins section, and ensure that “update add-ons automatically” is NOT ticked.

Install Unity web player version 5.1

Extract and run “UnityWebPlayerFull.exe” from here (originally retrieved from here)

Do NOT go to as the “Get Unity” button suggests — this page only provides you with version 4 of the web player. There are certain changes between versions 4 and 5, and even between the sub-versions, causing some games to only work on specific versions. For FD, this means we need 5.1.4