For Windows Phone 8 at least..... Possibly 7.5/7.8 (If 7.5 supports Marmelade SDK). Its developed by ArtOfBytes and its a tower defense type game. It is confirmed to be "coming soon".
Grave Defense HD-The Secret Lab: Time Portal (insane) level 21 - YouTube
Grave Defense HD-The Secret Lab: Time Portal (insane) level 21 - YouTube