You are downloading the Duet Adventure XAP file v18.104.22.168 for Windows Phone. Duet Adventure is a free and fun Action & Adventure game: Available to you many levels. You go around all the obstacles and go to the end faster ... You can now download the offline XAP file to install & try it.
Download Locations for Duet Adventure 22.214.171.124 XAP file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline XAP File To Install It Any More.
To try to install it manually from an SD card, you should choose one of the server location above to get the offline Duet Adventure XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.