You can only touch blocks that you have placed, (basically the floor is lava but without the lava)
Use /startctf to begin
Use /stopctf to end
Use /reload to reload all plugins if you encounter any problems
Warning - This plugin will take up your disk space in the form of a .yml file as you use it. The more you use it the more storage taken up. However, it is only a text file so it will stay very small (kilo bytes)