Position saving (granted you don't get killed or thrown off), infinite generation, leaderboards for kills and heights, purchasable weapons that you can buy at the cost of how many stairs you've passed (1 stair = 1 point). If you die, though, the weapons should disappear from your inventory. This is so it gets progressively harder, and the people at the beginning aren't at a disadvantage.
You've got somethin' goin here.
