Very true, unfortunately I doubt this will fit well as a gamemode on its own. There would have to be, Currency Possible in-game ranks In-game added perks to help you win to make the game more appealing. I don't think the above suits spleef very well. :p Spleef is more like a minigame, and it should be in the minigame section. Something has to be done to increase popularity of the minigame section. Thank you. Thanks!
Support. But i agree with @TADS4 and @IG_Pegasus it should be a gamemode. And i think it's possible too, look at Infection?