Jump Rush is the fourth Challenge Act of Green Hill Act 2 in the console/PC version of Sonic Generations. It is unlocked after clearing every Stage in the classic era and is playable only as Modern Sonic.
In this Challenge Act, Sonic must use Ramps, Springs, Dash Rings and his own jump to carry him over obstacles that lie in his path and reach the Goal Ring before time runs out. The mission begins simply, with rows of Ramps that help Sonic collect Rings while cutting a second or two off his time, but Sonic soon finds himself having to jump at exactly the right moment to pass through a Dash Ring or dodge an obstacle that comes seemingly out of nowhere. Once Sonic reaches the Goal, the Challenge Act is completed, and the player is graded according to his or her time. Every shortcut counts if Sonic is to achieve an S-rank by finishing in under one minute twenty seconds.