ability to dodge/roll/sidestep
ability to jump while sprintingabi
ability to attack while in air
greatly expanded weapon/armor types, the amount right now in game is kinda pitiful
reworking of leveling system. skill determines damage/stealthiness/etc and remove perks that increase them, replace passive perks with active, gameplay altering ones. combine weapon type perks together so people dont feel pigeon holed into picking axe, sword, or mace.
twohanders passively can hit more then one opponent at a time
vanity mod-ability to cover your armro with the visuals of another armor. so you can look good without being gimp.

My first thing will be "Cliffracers"