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.
This Challenge Act takes place in a highly modified version of Green Hill Act 2. While the stage progresses in a similar manner to the regular Act, there are additional gimmicks placed throughout, such as Jump Panels, Springs, and Dash Rings, that the player must utilize in order to reach the Goal Ring unscathed.
In this Challenge Act, Sonic must use the local gimmicks 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 Jump Panels 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 will be completed.