You have to try it! Basically, it's still Ts and CTs, but you can pick to be either of the 4 War3 races. Depending on which race you pick, you can get 4 special abilities that build up with the number of kills you get. For instance, humans get invisiblity and teleporation; undead gets vampiric aura which gives you life for doing damage and a move where when you die, you blow up all those arond you; elves get vines that can hold you in place and reincarnation; and orcs get like a really powerful nade and chain lightening. I'm just naming the skills that I remember as I haven't played it that much, but it was a really refreshing experience from playing 'normal' CS. 
Here's the site for the mod: http://spacedude.games-fed.com/
Here's the site for the mod: http://spacedude.games-fed.com/