Jumping ability, damage ability, all the abilities that are in the game just that you choose which ones you'd like. And probably should be on a point system.
I got a couple of ideas for the game...
-Add ragdolls/dead bodies
-Campaign world based on the WW2 maps
-Add your own abilities to your custom cape
-More characters in the chat menu
-More colors in the create a skin/cape part
There we go...