Story Mode is the primary game mode featured in Cookie Run: Tower of Adventures, following 
GingerBrave and his friends on their quest to find the Guardian Cookies, seal the Oven, and save the Pancake Tower! There are currently 11 Story Mode chapters available to play, with 9 of the 11 chapters additionally having a Hard Mode.
Hard Mode[]
Stage Rankings[]
Stage Rankings are a leaderboard that displays players' clear times for each stage, being separated by the difficulty that the stage was cleared on (being Normal or Hard Mode). The shorter the amount of time taken to clear a stage, the higher a player will place onto the rankings for that particular stage. The player who captures the shortest time on a stage (therefore being #1 on the leaderboard) will receive a special title declaring their mastery of that particular stage. You view these special titles here. It is currently unknown whether a title is revoked from a player if a different player takes the top spot in a stage ranking. While Normal Mode rankings require nothing more than a quick clear time, Hard Mode stages require the use of Flawless Mode in order to be counted towards the online leaderboard.
Flawless Mode[]
Flawless Mode is an optional toggle that makes Story Mode stages much more difficult and intense. While Flawless Mode is activated, stages will immediately end once the player takes damage from an outside source. Even if the player is shielded, the stage will still end once damage is taken, regardless of the Cookie's health bar not being lowered by said damage. Damage caused by the player/Cookie themself does not count as "taking damage" under the conditions of Flawless Mode. A good example of this would be 
Chili Pepper Cookie using her Ultimate, causing the Cookie to instantly lose 30% of her health. Flawless Mode would not count such an instance as "taking damage". Stage rankings for Hard Mode require the use of Flawless Mode.