Kinect Adventures

Time: 1 hour or less
Difficulty: 3/5-Medium/Hard

The time challenges are located under the Main Menu but you have to play through Adventures Mode to unlock them all. If you capable of getting Gold on other activities these time challenges should be easy. Just collect pins to keep your time going. There are only 6 maps to play, so this is much less time consuming than the other challenges which include 9 maps.

In this case, I suggest staying if at all possible on clouds/river banks. This is where you will get the most time pins. Time your jumps to the last second, so that way you don't fall short. Also remember that with 2 player you can double jump if you time it right.

REMEMBER: Speed isn't as important as getting the pins. Of course it is important, but you'll do much better trying to get all of the pins instead of just racing through.

This can be completed by going into timed mode and selecting River Rush. You have to have unlocked the timed challenges for them in adventure mode before you can attempt this.
There are only 6 levels you have to beat as opposed to 9 for the rallyball timed achivement (There are also 6 for reflex ridge). It should take less than an hour to earn this achievement and that includes plenty of time for retrying. I only had trouble on the third level, as I kept missing the ledges I was trying to jump onto and wasting time this way. To avoid this, I would suggest waiting until the last possible moment to jump, as this ensures you won't come up short and run out of time because of it.

After unlocking this mode through playing adventure mode you can play the timed River Rush time challenges. To win these the best way is to choose the higher routes because there are the most timed "pins"
Good luck and if u have any questions please let me know.

ps If u leave a negative vote please let me know why...