Unfortunately, as of January 12th 2021, the Flash Games on the Ninja Kiwi website will stop working. This was a decision taken by Adobe to end their Flash support and is outwith our control.
We did have a solution to this which was the Ninja Kiwi Archive on Steam (a free bundle of our website games which we planned to still work after Flash's end of life), but after further testing, it looks like that may no longer be viable and now these games may be inaccessible (at least temporarily if not permanently) as of the date above. We are actively looking into alternative options to keep these games alive, so be sure to keep an eye on our website's blog for updates on that, but we can't make any promises at this stage.
For more information about Flash closing down, you can read the Adobe End of Life guide - https://www.adobe.com/products/flashplayer/end-of-life.html