Sound compatibility issues with Niilu
The use of module-format background music tracks may be an issue on some systems. There is a compatibility patch available to the game which replaces the module tracks with ogg vorbis encoded music. Download it here.
Extract the contents of the folder to Niilu root folder and replace any asked files by choosing "yes" when asked of replacing files. The installation of the patch is also described in the patch package.
OS compatibility issues with Atomic Arena -series
Atomic Arena -games were made with old tools which are not fully compatible with the latest Windows operating systems such as Windows Vista. You might experience problems varying from crashes to slowdowns, which render the games unplayable.
These problems are often solved very easily with the following quick steps by enabling the compatibility mode with earlier Windows versions. The only files you need to do this procedure to are the executables (exe-files).
Access the exe-file's properties. Go to the Compatibility-tab (as pictured). Change the compatibility mode to either Windows 2000 or Windows XP. If you are still experiencing problems you might want to experiment with older compatibility modes too. This procedure applies to both Atomic Arena and Atomic Arena 2.
Other issues related to the Atomic Arena -series are widely covered in the bundled readme-files (readme.txt).