This Cactus Spleef Arena is one of the featured builds of my continuous project: Riverview City (http://www.planetminecraft.com/project/riverview-city/)! I created this schematic for you guys to download as a separate build for everyone to use! There are command blocks used in this arena, mainly to teleport you in and out of the arena. The coordinates in the command blocks will differ from the coordinates on your map.

The basic idea of the game is to fight with an object that has knockback (I would suggest knockback 4/5) applied onto it, and the goal is to knock your opponents into the cacti to kill them.

I would really appreciate it if you guys use this build, to place a sign somewhere on/in the arena to credit me. If you upload this arena as a picture for your server, I would also appreciate it if you state that I built the arena! Thanks for checking out this arena, and don't forget to drop a diamond if you liked it! 

This arena is also featured on my server, Square Pixels! Come check it out: http://www.planetminecraft.com/server/square-pixels/