atWar uses Microsoft Silverlight plugin - it's great for complex web games, very smooth, less resource-hungry and less obtrusive than Flash. One 15-sec installation and it won't bother you again.

If you are using Chrome browser and already have Silverlight installed, please make sure you have NPAPI support enabled.
To do so, follow these simple steps:

You can also try running the game in another browser or download and install the game on desktop.