The Arena mod was originally released in 2002. This mod adds bots to the multiplayer. Bots acts like players and they also can use several augmentations. The mod also includes some singleplayer content. It replaces several weapons, modifies augmentations, adds equipment shops and makes similar small but useful changes and ships with 5 multiplayer maps. After the first release the mod was abandoned and the best features migrated to Hardcore DX. So basically Arena is just a kind of alpha preview of the first versions or the Hardcore DX mod, but it’s quite stable, playable and funny and includes several features that were not included to Hardcore DX. Since the development of Arena mod was abandoned years ago we can't provide any updates, bug fixes or support for this mod. This version is identical with the version released in 2002, but features an easier way of installation and a slightly updated documentation.
This picture looks like a fatal scene of a basement "Big Game" party with chips and ketchup gone wrong with by carbon monoxide
LOL leilei xD